20972863 has 4 divisors (see below), whose sum is σ = 21460648. Its totient is φ = 20485080.

The previous prime is 20972851. The next prime is 20972867. The reversal of 20972863 is 36827902.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20972863 - 2⁹ = 20972351 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 (20972867) 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, 243828 + ... + 243913.

It is an arithmetic number, because the mean of its divisors is an integer number (5365162).

Almost surely, 2^20972863 is an apocalyptic number.

20972863 is a deficient number, since it is larger than the sum of its proper divisors (487785).

20972863 is an equidigital number, since it uses as much as digits as its factorization.

20972863 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 487784.

The product of its (nonzero) digits is 36288, while the sum is 37.

The square root of 20972863 is about 4579.6138483501. The cubic root of 20972863 is about 275.7735268476.

The spelling of 20972863 in words is "twenty million, nine hundred seventy-two thousand, eight hundred sixty-three".