21053998 has 16 divisors (see below), whose sum is σ = 36338400. Its totient is φ = 8961696.

The previous prime is 21053987. The next prime is 21054017. The reversal of 21053998 is 89935012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2961 + ... + 7132.

It is an arithmetic number, because the mean of its divisors is an integer number (2271150).

Almost surely, 2^21053998 is an apocalyptic number.

21053998 is a deficient number, since it is larger than the sum of its proper divisors (15284402).

21053998 is a wasteful number, since it uses less digits than its factorization.

21053998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10251.

The product of its (nonzero) digits is 19440, while the sum is 37.

The square root of 21053998 is about 4588.4635772773. The cubic root of 21053998 is about 276.1286857023.

The spelling of 21053998 in words is "twenty-one million, fifty-three thousand, nine hundred ninety-eight".