228172640256 has 520 divisors, whose sum is σ = 752039169024. Its totient is φ = 68359127040.

The previous prime is 228172640249. The next prime is 228172640257. The reversal of 228172640256 is 652046271822.

228172640256 is a `hidden beast` number, since 2 + 28 + 172 + 6 + 402 + 56 = 666.

It is a super-2 number, since 2×228172640256² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (228172640257) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 375901905 + ... + 375902511.

Almost surely, 2^228172640256 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 228172640256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (376019584512).

228172640256 is an abundant number, since it is smaller than the sum of its proper divisors (523866528768).

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

228172640256 is a wasteful number, since it uses less digits than its factorization.

228172640256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 757 (or 726 counting only the distinct ones).

The product of its (nonzero) digits is 645120, while the sum is 45.

The spelling of 228172640256 in words is "two hundred twenty-eight billion, one hundred seventy-two million, six hundred forty thousand, two hundred fifty-six".