22731521 has 8 divisors (see below), whose sum is σ = 23794560. Its totient is φ = 21674752.

The previous prime is 22731517. The next prime is 22731551. The reversal of 22731521 is 12513722.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 22731521 - 2² = 22731517 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (22731551) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6881 + ... + 9633.

It is an arithmetic number, because the mean of its divisors is an integer number (2974320).

Almost surely, 2^22731521 is an apocalyptic number.

22731521 is the 2753-rd octagonal number.

It is an amenable number.

22731521 is a deficient number, since it is larger than the sum of its proper divisors (1063039).

22731521 is a wasteful number, since it uses less digits than its factorization.

22731521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3135.

The product of its digits is 840, while the sum is 23.

The square root of 22731521 is about 4767.7584880109. The cubic root of 22731521 is about 283.2758156217.

The spelling of 22731521 in words is "twenty-two million, seven hundred thirty-one thousand, five hundred twenty-one".