13123521540 has 72 divisors (see below), whose sum is σ = 41903184960. Its totient is φ = 3315415104.

The previous prime is 13123521533. The next prime is 13123521547. The reversal of 13123521540 is 4512532131.

13123521540 is a `hidden beast` number, since 13 + 123 + 521 + 5 + 4 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (13123521533) and next prime (13123521547).

It is a super-2 number, since 2×13123521540² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (13123521547) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1915224 + ... + 1922063.

It is an arithmetic number, because the mean of its divisors is an integer number (581988680).

Almost surely, 2^13123521540 is an apocalyptic number.

13123521540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13123521540 is an abundant number, since it is smaller than the sum of its proper divisors (28779663420).

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

13123521540 is a wasteful number, since it uses less digits than its factorization.

13123521540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3837321 (or 3837316 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The spelling of 13123521540 in words is "thirteen billion, one hundred twenty-three million, five hundred twenty-one thousand, five hundred forty".