20812951 has 4 divisors (see below), whose sum is σ = 20823304. Its totient is φ = 20802600.

The previous prime is 20812943. The next prime is 20812973. The reversal of 20812951 is 15921802.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 20812951 - 2³ = 20812943 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20812921) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1080 + ... + 6541.

It is an arithmetic number, because the mean of its divisors is an integer number (5205826).

Almost surely, 2^20812951 is an apocalyptic number.

20812951 is a deficient number, since it is larger than the sum of its proper divisors (10353).

20812951 is an equidigital number, since it uses as much as digits as its factorization.

20812951 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10352.

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 20812951 is about 4562.1213267514. The cubic root of 20812951 is about 275.0708401522.

The spelling of 20812951 in words is "twenty million, eight hundred twelve thousand, nine hundred fifty-one".