23151891 has 16 divisors (see below), whose sum is σ = 35479808. Its totient is φ = 13154400.

The previous prime is 23151883. The next prime is 23151907. The reversal of 23151891 is 19815132.

It is not a de Polignac number, because 23151891 - 2³ = 23151883 is a prime.

It is not an unprimeable number, because it can be changed into a prime (23151811) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 756 + ... + 6846.

It is an arithmetic number, because the mean of its divisors is an integer number (2217488).

Almost surely, 2^23151891 is an apocalyptic number.

23151891 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

23151891 is a deficient number, since it is larger than the sum of its proper divisors (12327917).

23151891 is a wasteful number, since it uses less digits than its factorization.

23151891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6282.

The product of its digits is 2160, while the sum is 30.

The square root of 23151891 is about 4811.6411960993. The cubic root of 23151891 is about 285.0113507329.

It can be divided in two parts, 23151 and 891, that added together give a palindrome (24042).

The spelling of 23151891 in words is "twenty-three million, one hundred fifty-one thousand, eight hundred ninety-one".