23140640 has 24 divisors (see below), whose sum is σ = 54670140. Its totient is φ = 9256192.

The previous prime is 23140609. The next prime is 23140657. The reversal of 23140640 is 4604132.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 22316176 + 824464 = 4724^2 + 908^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72155 + ... + 72474.

Almost surely, 2^23140640 is an apocalyptic number.

23140640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

23140640 is an abundant number, since it is smaller than the sum of its proper divisors (31529500).

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

23140640 is a wasteful number, since it uses less digits than its factorization.

23140640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144644 (or 144636 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 23140640 is about 4810.4719103223. The cubic root of 23140640 is about 284.9651747742.

Adding to 23140640 its reverse (4604132), we get a palindrome (27744772).

The spelling of 23140640 in words is "twenty-three million, one hundred forty thousand, six hundred forty".