23931540 has 36 divisors (see below), whose sum is σ = 72592884. Its totient is φ = 6381696.

The previous prime is 23931533. The next prime is 23931547. The reversal of 23931540 is 4513932.

It is an interprime number because it is at equal distance from previous prime (23931533) and next prime (23931547).

It can be written as a sum of positive squares in 2 ways, for example, as 12194064 + 11737476 = 3492^2 + 3426^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23931547) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 66297 + ... + 66656.

It is an arithmetic number, because the mean of its divisors is an integer number (2016469).

Almost surely, 2^23931540 is an apocalyptic number.

23931540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

23931540 is an abundant number, since it is smaller than the sum of its proper divisors (48661344).

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

23931540 is a wasteful number, since it uses less digits than its factorization.

23931540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132968 (or 132963 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 27.

The square root of 23931540 is about 4891.9873262305. The cubic root of 23931540 is about 288.1753850712.

The spelling of 23931540 in words is "twenty-three million, nine hundred thirty-one thousand, five hundred forty".