2155731788 has 12 divisors (see below), whose sum is σ = 4311463632. Its totient is φ = 923885040.

The previous prime is 2155731761. The next prime is 2155731821. The reversal of 2155731788 is 8871375512.

It is a happy number.

2155731788 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

2155731788 is an admirable number.

It is a hoax number, since the sum of its digits (47) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38495183 + ... + 38495238.

It is an arithmetic number, because the mean of its divisors is an integer number (359288636).

Almost surely, 2^2155731788 is an apocalyptic number.

2155731788 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

2155731788 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

2155731788 is a wasteful number, since it uses less digits than its factorization.

2155731788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76990432 (or 76990430 counting only the distinct ones).

The product of its digits is 470400, while the sum is 47.

The square root of 2155731788 is about 46429.8587979761. The cubic root of 2155731788 is about 1291.8088096160.

The spelling of 2155731788 in words is "two billion, one hundred fifty-five million, seven hundred thirty-one thousand, seven hundred eighty-eight".