21498920 has 32 divisors (see below), whose sum is σ = 49290120. Its totient is φ = 8436480.

The previous prime is 21498913. The next prime is 21498949. The reversal of 21498920 is 2989412.

It can be written as a sum of positive squares in 4 ways, for example, as 16144324 + 5354596 = 4018^2 + 2314^2 .

It is a super-2 number, since 2×21498920² = 924407122332800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2951 + ... + 7190.

Almost surely, 2^21498920 is an apocalyptic number.

21498920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21498920 is an abundant number, since it is smaller than the sum of its proper divisors (27791200).

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

21498920 is a wasteful number, since it uses less digits than its factorization.

21498920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10205 (or 10201 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 21498920 is about 4636.6927868902. The cubic root of 21498920 is about 278.0602322779.

The spelling of 21498920 in words is "twenty-one million, four hundred ninety-eight thousand, nine hundred twenty".