21053020 has 24 divisors (see below), whose sum is σ = 44297568. Its totient is φ = 8404800.

The previous prime is 21053017. The next prime is 21053041. The reversal of 21053020 is 2035012.

It is a super-2 number, since 2×21053020² = 886459302240800, which contains 22 as substring.

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, 19905 + ... + 20935.

It is an arithmetic number, because the mean of its divisors is an integer number (1845732).

Almost surely, 2^21053020 is an apocalyptic number.

21053020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21053020 is an abundant number, since it is smaller than the sum of its proper divisors (23244548).

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

21053020 is a wasteful number, since it uses less digits than its factorization.

21053020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2061 (or 2059 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 13.

The square root of 21053020 is about 4588.3570044189. The cubic root of 21053020 is about 276.1244100609.

Adding to 21053020 its reverse (2035012), we get a palindrome (23088032).

The spelling of 21053020 in words is "twenty-one million, fifty-three thousand, twenty".