22487521 has 6 divisors (see below), whose sum is σ = 26159010. Its totient is φ = 19274976.

The previous prime is 22487519. The next prime is 22487539. The reversal of 22487521 is 12578422.

22487521 = T₄₇₈ + T₄₇₉ + ... + T₆₂₄.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 18835600 + 3651921 = 4340^2 + 1911^2 .

It is not a de Polignac number, because 22487521 - 2¹ = 22487519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (22487501) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 229416 + ... + 229513.

It is an arithmetic number, because the mean of its divisors is an integer number (4359835).

Almost surely, 2^22487521 is an apocalyptic number.

It is an amenable number.

22487521 is a deficient number, since it is larger than the sum of its proper divisors (3671489).

22487521 is an equidigital number, since it uses as much as digits as its factorization.

22487521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 458943 (or 458936 counting only the distinct ones).

The product of its digits is 8960, while the sum is 31.

The square root of 22487521 is about 4742.1009057168. The cubic root of 22487521 is about 282.2586070630.

Subtracting from 22487521 its reverse (12578422), we obtain a palindrome (9909099).

The spelling of 22487521 in words is "twenty-two million, four hundred eighty-seven thousand, five hundred twenty-one".