20873651 has 4 divisors (see below), whose sum is σ = 21215904. Its totient is φ = 20531400.

The previous prime is 20873639. The next prime is 20873653. The reversal of 20873651 is 15637802.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20873651 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20873653) 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, 171035 + ... + 171156.

It is an arithmetic number, because the mean of its divisors is an integer number (5303976).

Almost surely, 2^20873651 is an apocalyptic number.

20873651 is a deficient number, since it is larger than the sum of its proper divisors (342253).

20873651 is an equidigital number, since it uses as much as digits as its factorization.

20873651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 342252.

The product of its (nonzero) digits is 10080, while the sum is 32.

The square root of 20873651 is about 4568.7690902474. The cubic root of 20873651 is about 275.3379910307.

The spelling of 20873651 in words is "twenty million, eight hundred seventy-three thousand, six hundred fifty-one".