64217149920 has 1440 divisors, whose sum is σ = 298456915680. Its totient is φ = 12843048960.

The previous prime is 64217149901. The next prime is 64217149921. The reversal of 64217149920 is 2994171246.

It is a tau number, because it is divible by the number of its divisors (1440).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64217149921) by changing a digit.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 202577602 + ... + 202577918.

It is an arithmetic number, because the mean of its divisors is an integer number (207261747).

Almost surely, 2^64217149920 is an apocalyptic number.

64217149920 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 64217149920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (149228457840).

64217149920 is an abundant number, since it is smaller than the sum of its proper divisors (234239765760).

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

64217149920 is a wasteful number, since it uses less digits than its factorization.

64217149920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 398 (or 374 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The spelling of 64217149920 in words is "sixty-four billion, two hundred seventeen million, one hundred forty-nine thousand, nine hundred twenty".