21053874 has 16 divisors (see below), whose sum is σ = 42155712. Its totient is φ = 7009968.

The previous prime is 21053873. The next prime is 21053887. The reversal of 21053874 is 47835012.

It is a super-2 number, since 2×21053874² = 886531220815752, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21053873) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6472 + ... + 9164.

It is an arithmetic number, because the mean of its divisors is an integer number (2634732).

Almost surely, 2^21053874 is an apocalyptic number.

21053874 is an abundant number, since it is smaller than the sum of its proper divisors (21101838).

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

21053874 is a wasteful number, since it uses less digits than its factorization.

21053874 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4001.

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 21053874 is about 4588.4500651091. The cubic root of 21053874 is about 276.1281436038.

Adding to 21053874 its reverse (47835012), we get a palindrome (68888886).

The spelling of 21053874 in words is "twenty-one million, fifty-three thousand, eight hundred seventy-four".