15513231123 has 36 divisors (see below), whose sum is σ = 24606206352. Its totient is φ = 9412079040.

The previous prime is 15513231101. The next prime is 15513231143. The reversal of 15513231123 is 32113231551.

15513231123 is a `hidden beast` number, since 1 + 5 + 513 + 23 + 1 + 123 = 666.

It is not a de Polignac number, because 15513231123 - 2⁵ = 15513231091 is a prime.

It is a super-2 number, since 2×15513231123² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (15513231143) 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, 36165 + ... + 179817.

It is an arithmetic number, because the mean of its divisors is an integer number (683505732).

Almost surely, 2^15513231123 is an apocalyptic number.

15513231123 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

15513231123 is a deficient number, since it is larger than the sum of its proper divisors (9092975229).

15513231123 is a wasteful number, since it uses less digits than its factorization.

15513231123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143756 (or 143740 counting only the distinct ones).

The product of its digits is 2700, while the sum is 27.

Adding to 15513231123 its reverse (32113231551), we get a palindrome (47626462674).

The spelling of 15513231123 in words is "fifteen billion, five hundred thirteen million, two hundred thirty-one thousand, one hundred twenty-three".