15555257172 has 576 divisors, whose sum is σ = 53137011200. Its totient is φ = 3950456832.

The previous prime is 15555257149. The next prime is 15555257189. The reversal of 15555257172 is 27175255551.

15555257172 is a `hidden beast` number, since 1 + 5 + 5 + 5 + 5 + 2 + 571 + 72 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 160363428 + ... + 160363524.

Almost surely, 2^15555257172 is an apocalyptic number.

15555257172 is a gapful number since it is divisible by the number (12) 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 15555257172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26568505600).

15555257172 is an abundant number, since it is smaller than the sum of its proper divisors (37581754028).

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

15555257172 is a wasteful number, since it uses less digits than its factorization.

15555257172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187 (or 159 counting only the distinct ones).

The product of its digits is 612500, while the sum is 45.

The spelling of 15555257172 in words is "fifteen billion, five hundred fifty-five million, two hundred fifty-seven thousand, one hundred seventy-two".