2158718931 has 12 divisors (see below), whose sum is σ = 3233636952. Its totient is φ = 1439145792.

The previous prime is 2158718911. The next prime is 2158718951. The reversal of 2158718931 is 1398178512.

2158718931 is a `hidden beast` number, since 21 + 587 + 18 + 9 + 31 = 666.

It is an interprime number because it is at equal distance from previous prime (2158718911) and next prime (2158718951).

It is not a de Polignac number, because 2158718931 - 2⁶ = 2158718867 is a prime.

It is a super-2 number, since 2×2158718931² = 9320134846115565522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2158718911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4441566 + ... + 4442051.

It is an arithmetic number, because the mean of its divisors is an integer number (269469746).

Almost surely, 2^2158718931 is an apocalyptic number.

2158718931 is a deficient number, since it is larger than the sum of its proper divisors (1074918021).

2158718931 is an frugal number, since it uses more digits than its factorization.

2158718931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8883632 (or 8883620 counting only the distinct ones).

The product of its digits is 120960, while the sum is 45.

The square root of 2158718931 is about 46462.0160023217. The cubic root of 2158718931 is about 1292.4052098237.

The spelling of 2158718931 in words is "two billion, one hundred fifty-eight million, seven hundred eighteen thousand, nine hundred thirty-one".