621728172 has 36 divisors (see below), whose sum is σ = 1692483520. Its totient is φ = 191300832.

The previous prime is 621728171. The next prime is 621728179. The reversal of 621728172 is 271827126.

621728172 is a `hidden beast` number, since 621 + 7 + 28 + 1 + 7 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-3 number, since 3×621728172³ (a number of 27 digits) contains 333 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (621728171) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 663772 + ... + 664707.

Almost surely, 2^621728172 is an apocalyptic number.

It is an amenable number.

621728172 is an abundant number, since it is smaller than the sum of its proper divisors (1070755348).

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

621728172 is a wasteful number, since it uses less digits than its factorization.

621728172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1328502 (or 1328497 counting only the distinct ones).

The product of its digits is 18816, while the sum is 36.

The square root of 621728172 is about 24934.4775762397. The cubic root of 621728172 is about 853.4934297737.

The spelling of 621728172 in words is "six hundred twenty-one million, seven hundred twenty-eight thousand, one hundred seventy-two".