642726720 has 336 divisors, whose sum is σ = 2388851712. Its totient is φ = 158146560.

The previous prime is 642726713. The next prime is 642726787. The reversal of 642726720 is 27627246.

642726720 is a `hidden beast` number, since 642 + 7 + 2 + 6 + 7 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2053284 + ... + 2053596.

Almost surely, 2^642726720 is an apocalyptic number.

642726720 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 642726720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1194425856).

642726720 is an abundant number, since it is smaller than the sum of its proper divisors (1746124992).

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

642726720 is a wasteful number, since it uses less digits than its factorization.

642726720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 390 (or 377 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 36.

The square root of 642726720 is about 25352.0555379638. The cubic root of 642726720 is about 862.9960045592.

The spelling of 642726720 in words is "six hundred forty-two million, seven hundred twenty-six thousand, seven hundred twenty".