21425490 has 48 divisors (see below), whose sum is σ = 57634200. Its totient is φ = 5515776.

The previous prime is 21425477. The next prime is 21425497. The reversal of 21425490 is 9452412.

It can be written as a sum of positive squares in 4 ways, for example, as 12299049 + 9126441 = 3507^2 + 3021^2 .

It is not an unprimeable number, because it can be changed into a prime (21425497) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1495 + ... + 6714.

Almost surely, 2^21425490 is an apocalyptic number.

21425490 is an abundant number, since it is smaller than the sum of its proper divisors (36208710).

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

21425490 is a wasteful number, since it uses less digits than its factorization.

21425490 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8251 (or 8248 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 21425490 is about 4628.7676545707. The cubic root of 21425490 is about 277.7432977054.

The spelling of 21425490 in words is "twenty-one million, four hundred twenty-five thousand, four hundred ninety".