20651943 has 16 divisors (see below), whose sum is σ = 30033920. Its totient is φ = 12546144.

The previous prime is 20651933. The next prime is 20651959. The reversal of 20651943 is 34915602.

It is a de Polignac number, because none of the positive numbers 2^k-20651943 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 20651943.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20651933) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 271 + ... + 6432.

It is an arithmetic number, because the mean of its divisors is an integer number (1877120).

Almost surely, 2^20651943 is an apocalyptic number.

20651943 is a deficient number, since it is larger than the sum of its proper divisors (9381977).

20651943 is a wasteful number, since it uses less digits than its factorization.

20651943 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6798.

The product of its (nonzero) digits is 6480, while the sum is 30.

The square root of 20651943 is about 4544.4408897025. The cubic root of 20651943 is about 274.3596915337.

The spelling of 20651943 in words is "twenty million, six hundred fifty-one thousand, nine hundred forty-three".