20662651 has 4 divisors (see below), whose sum is σ = 20673904. Its totient is φ = 20651400.

The previous prime is 20662643. The next prime is 20662693. The reversal of 20662651 is 15626602.

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, and also an emirpimes, since its reverse is a distinct semiprime: 15626602 = 2 ⋅7813301.

It is a cyclic number.

It is not a de Polignac number, because 20662651 - 2³ = 20662643 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20662051) 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, 2160 + ... + 6781.

It is an arithmetic number, because the mean of its divisors is an integer number (5168476).

Almost surely, 2^20662651 is an apocalyptic number.

20662651 is a deficient number, since it is larger than the sum of its proper divisors (11253).

20662651 is an equidigital number, since it uses as much as digits as its factorization.

20662651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11252.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 20662651 is about 4545.6188797566. The cubic root of 20662651 is about 274.4071016969.

The spelling of 20662651 in words is "twenty million, six hundred sixty-two thousand, six hundred fifty-one".