2156931 has 36 divisors (see below), whose sum is σ = 3728712. Its totient is φ = 1197504.

The previous prime is 2156897. The next prime is 2156939. The reversal of 2156931 is 1396512.

It is not a de Polignac number, because 2156931 - 2⁶ = 2156867 is a prime.

It is a super-2 number, since 2×2156931² = 9304702677522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 2156895 and 2156904.

It is not an unprimeable number, because it can be changed into a prime (2156939) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 29511 + ... + 29583.

2^2156931 is an apocalyptic number.

2156931 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

2156931 is a deficient number, since it is larger than the sum of its proper divisors (1571781).

2156931 is a wasteful number, since it uses less digits than its factorization.

2156931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160 (or 150 counting only the distinct ones).

The product of its digits is 1620, while the sum is 27.

The square root of 2156931 is about 1468.6493795321. The cubic root of 2156931 is about 129.2048305312.

The spelling of 2156931 in words is "two million, one hundred fifty-six thousand, nine hundred thirty-one".