23212521 has 16 divisors (see below), whose sum is σ = 35499520. Its totient is φ = 14975280.

The previous prime is 23212517. The next prime is 23212523. The reversal of 23212521 is 12521232.

It is not a de Polignac number, because 23212521 - 2² = 23212517 is a prime.

It is a super-2 number, since 2×23212521² = 1077642262350882, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 23212494 and 23212503.

It is not an unprimeable number, because it can be changed into a prime (23212523) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13030 + ... + 14703.

It is an arithmetic number, because the mean of its divisors is an integer number (2218720).

Almost surely, 2^23212521 is an apocalyptic number.

It is an amenable number.

23212521 is a deficient number, since it is larger than the sum of its proper divisors (12286999).

23212521 is a wasteful number, since it uses less digits than its factorization.

23212521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27773 (or 27767 counting only the distinct ones).

The product of its digits is 240, while the sum is 18.

The square root of 23212521 is about 4817.9374217605. The cubic root of 23212521 is about 285.2599290693.

Adding to 23212521 its reverse (12521232), we get a palindrome (35733753).

The spelling of 23212521 in words is "twenty-three million, two hundred twelve thousand, five hundred twenty-one".