646769242955520 has 576 divisors, whose sum is σ = 2328163617024000. Its totient is φ = 169991091486720.

The previous prime is 646769242955447. The next prime is 646769242955527. The reversal of 646769242955520 is 25559242967646.

646769242955520 is a `hidden beast` number, since 6 + 4 + 6 + 7 + 6 + 9 + 2 + 4 + 2 + 95 + 5 + 520 = 666.

646769242955520 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (576).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646769242955527) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 8462980029 + ... + 8463056451.

It is an arithmetic number, because the mean of its divisors is an integer number (4041950724000).

Almost surely, 2^{646769242955520} is an apocalyptic number.

646769242955520 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 646769242955520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1164081808512000).

646769242955520 is an abundant number, since it is smaller than the sum of its proper divisors (1681394374068480).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

646769242955520 is a wasteful number, since it uses less digits than its factorization.

646769242955520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79973 (or 79953 counting only the distinct ones).

The product of its (nonzero) digits is 1959552000, while the sum is 72.

The spelling of 646769242955520 in words is "six hundred forty-six trillion, seven hundred sixty-nine billion, two hundred forty-two million, nine hundred fifty-five thousand, five hundred twenty".