23181451520 has 36 divisors (see below), whose sum is σ = 55526823660. Its totient is φ = 9272580096.

The previous prime is 23181451493. The next prime is 23181451523. The reversal of 23181451520 is 2515418132.

It can be written as a sum of positive squares in 2 ways, for example, as 17874620416 + 5306831104 = 133696^2 + 72848^2 .

It is a super-2 number, since 2×23181451520² (a number of 22 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is not an unprimeable number, because it can be changed into a prime (23181451523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9053975 + ... + 9056534.

Almost surely, 2^23181451520 is an apocalyptic number.

23181451520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

23181451520 is an abundant number, since it is smaller than the sum of its proper divisors (32345372140).

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

23181451520 is an equidigital number, since it uses as much as digits as its factorization.

23181451520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18110530 (or 18110516 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 32.

Adding to 23181451520 its reverse (2515418132), we get a palindrome (25696869652).

The spelling of 23181451520 in words is "twenty-three billion, one hundred eighty-one million, four hundred fifty-one thousand, five hundred twenty".