21053131 has 8 divisors (see below), whose sum is σ = 23527728. Its totient is φ = 18672000.

The previous prime is 21053129. The next prime is 21053173. The reversal of 21053131 is 13135012.

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 21053131 - 2¹ = 21053129 is a prime.

It is a super-2 number, since 2×21053131² = 886468649806322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21053731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22890 + ... + 23791.

It is an arithmetic number, because the mean of its divisors is an integer number (2940966).

Almost surely, 2^21053131 is an apocalyptic number.

21053131 is a deficient number, since it is larger than the sum of its proper divisors (2474597).

21053131 is a wasteful number, since it uses less digits than its factorization.

21053131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46733.

The product of its (nonzero) digits is 90, while the sum is 16.

The square root of 21053131 is about 4588.3691002359. The cubic root of 21053131 is about 276.1248953398.

Adding to 21053131 its reverse (13135012), we get a palindrome (34188143).

The spelling of 21053131 in words is "twenty-one million, fifty-three thousand, one hundred thirty-one".