21053137 has 8 divisors (see below), whose sum is σ = 24515136. Its totient is φ = 17704752.

The previous prime is 21053129. The next prime is 21053173. The reversal of 21053137 is 73135012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21053137 - 2³ = 21053129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21053107) 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, 28003 + ... + 28744.

It is an arithmetic number, because the mean of its divisors is an integer number (3064392).

Almost surely, 2^21053137 is an apocalyptic number.

It is an amenable number.

21053137 is a deficient number, since it is larger than the sum of its proper divisors (3461999).

21053137 is an equidigital number, since it uses as much as digits as its factorization.

21053137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56807.

The product of its (nonzero) digits is 630, while the sum is 22.

The square root of 21053137 is about 4588.3697540630. The cubic root of 21053137 is about 276.1249215710.

Adding to 21053137 its reverse (73135012), we get a palindrome (94188149).

The spelling of 21053137 in words is "twenty-one million, fifty-three thousand, one hundred thirty-seven".