23121515151 has 16 divisors (see below), whose sum is σ = 39147539200. Its totient is φ = 13212294264.

The previous prime is 23121515119. The next prime is 23121515191. The reversal of 23121515151 is 15151512132.

It is a happy number.

23121515151 is a `hidden beast` number, since 23 + 121 + 5 + 1 + 515 + 1 = 666.

It is not a de Polignac number, because 23121515151 - 2⁵ = 23121515119 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23121515111) 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, 61167841 + ... + 61168218.

It is an arithmetic number, because the mean of its divisors is an integer number (2446721200).

Almost surely, 2^23121515151 is an apocalyptic number.

23121515151 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

23121515151 is a deficient number, since it is larger than the sum of its proper divisors (16026024049).

23121515151 is a wasteful number, since it uses less digits than its factorization.

23121515151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122336075 (or 122336069 counting only the distinct ones).

The product of its digits is 1500, while the sum is 27.

The spelling of 23121515151 in words is "twenty-three billion, one hundred twenty-one million, five hundred fifteen thousand, one hundred fifty-one".