23172640 has 24 divisors (see below), whose sum is σ = 54745740. Its totient is φ = 9268992.

The previous prime is 23172623. The next prime is 23172641. The reversal of 23172640 is 4627132.

It can be written as a sum of positive squares in 2 ways, for example, as 22014864 + 1157776 = 4692^2 + 1076^2 .

It is not an unprimeable number, because it can be changed into a prime (23172641) 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, 72255 + ... + 72574.

Almost surely, 2^23172640 is an apocalyptic number.

23172640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

23172640 is an abundant number, since it is smaller than the sum of its proper divisors (31573100).

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

23172640 is a wasteful number, since it uses less digits than its factorization.

23172640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144844 (or 144836 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 25.

The square root of 23172640 is about 4813.7968382556. The cubic root of 23172640 is about 285.0964688305.

Adding to 23172640 its reverse (4627132), we get a palindrome (27799772).

The spelling of 23172640 in words is "twenty-three million, one hundred seventy-two thousand, six hundred forty".