20618651251 has 4 divisors (see below), whose sum is σ = 22493074104. Its totient is φ = 18744228400.

The previous prime is 20618651219. The next prime is 20618651257. The reversal of 20618651251 is 15215681602.

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 20618651251 - 2⁵ = 20618651219 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20618651251.

It is not an unprimeable number, because it can be changed into a prime (20618651257) 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, 937211410 + ... + 937211431.

It is an arithmetic number, because the mean of its divisors is an integer number (5623268526).

Almost surely, 2^20618651251 is an apocalyptic number.

20618651251 is a deficient number, since it is larger than the sum of its proper divisors (1874422853).

20618651251 is a wasteful number, since it uses less digits than its factorization.

20618651251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1874422852.

The product of its (nonzero) digits is 28800, while the sum is 37.

The spelling of 20618651251 in words is "twenty billion, six hundred eighteen million, six hundred fifty-one thousand, two hundred fifty-one".