23321640 has 64 divisors (see below), whose sum is σ = 70646400. Its totient is φ = 6158592.

The previous prime is 23321621. The next prime is 23321653. The reversal of 23321640 is 4612332.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12189 + ... + 13971.

It is an arithmetic number, because the mean of its divisors is an integer number (1103850).

Almost surely, 2^23321640 is an apocalyptic number.

23321640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 23321640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35323200).

23321640 is an abundant number, since it is smaller than the sum of its proper divisors (47324760).

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

23321640 is a wasteful number, since it uses less digits than its factorization.

23321640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1906 (or 1902 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 21.

The square root of 23321640 is about 4829.2483887247. The cubic root of 23321640 is about 285.7062202485.

Adding to 23321640 its reverse (4612332), we get a palindrome (27933972).

The spelling of 23321640 in words is "twenty-three million, three hundred twenty-one thousand, six hundred forty".