23261721 has 12 divisors (see below), whose sum is σ = 36079632. Its totient is φ = 13292328.

The previous prime is 23261657. The next prime is 23261723. The reversal of 23261721 is 12716232.

It is not a de Polignac number, because 23261721 - 2⁶ = 23261657 is a prime.

It is a super-2 number, since 2×23261721² = 1082215327763682, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 23261691 and 23261700.

It is not an unprimeable number, because it can be changed into a prime (23261723) 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, 78975 + ... + 79268.

It is an arithmetic number, because the mean of its divisors is an integer number (3006636).

Almost surely, 2^23261721 is an apocalyptic number.

23261721 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

23261721 is a deficient number, since it is larger than the sum of its proper divisors (12817911).

23261721 is a wasteful number, since it uses less digits than its factorization.

23261721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158260 (or 158253 counting only the distinct ones).

The product of its digits is 1008, while the sum is 24.

The square root of 23261721 is about 4823.0406384355. The cubic root of 23261721 is about 285.4613273345.

Adding to 23261721 its reverse (12716232), we get a palindrome (35977953).

The spelling of 23261721 in words is "twenty-three million, two hundred sixty-one thousand, seven hundred twenty-one".