20556157272 has 128 divisors (see below), whose sum is σ = 60148915200. Its totient is φ = 5732633088.

The previous prime is 20556157231. The next prime is 20556157289. The reversal of 20556157272 is 27275165502.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1748229 + ... + 1759947.

It is an arithmetic number, because the mean of its divisors is an integer number (469913400).

Almost surely, 2^20556157272 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20556157272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30074457600).

20556157272 is an abundant number, since it is smaller than the sum of its proper divisors (39592757928).

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

20556157272 is a wasteful number, since it uses less digits than its factorization.

20556157272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11985 (or 11981 counting only the distinct ones).

The product of its (nonzero) digits is 294000, while the sum is 42.

The spelling of 20556157272 in words is "twenty billion, five hundred fifty-six million, one hundred fifty-seven thousand, two hundred seventy-two".