20812137 has 4 divisors (see below), whose sum is σ = 27749520. Its totient is φ = 13874756.

The previous prime is 20812123. The next prime is 20812139. The reversal of 20812137 is 73121802.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20812137 - 2²⁰ = 19763561 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20812139) 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 3 ways as a sum of consecutive naturals, for example, 3468687 + ... + 3468692.

It is an arithmetic number, because the mean of its divisors is an integer number (6937380).

Almost surely, 2^20812137 is an apocalyptic number.

It is an amenable number.

20812137 is a deficient number, since it is larger than the sum of its proper divisors (6937383).

20812137 is an equidigital number, since it uses as much as digits as its factorization.

20812137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6937382.

The product of its (nonzero) digits is 672, while the sum is 24.

The square root of 20812137 is about 4562.0321129953. The cubic root of 20812137 is about 275.0672540744.

Adding to 20812137 its reverse (73121802), we get a palindrome (93933939).

The spelling of 20812137 in words is "twenty million, eight hundred twelve thousand, one hundred thirty-seven".