21802164907 has 2 divisors, whose sum is σ = 21802164908. Its totient is φ = 21802164906.

The previous prime is 21802164893. The next prime is 21802164911. The reversal of 21802164907 is 70946120812.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21802164907 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21802164907.

It is not a weakly prime, because it can be changed into another prime (21802114907) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10901082453 + 10901082454.

It is an arithmetic number, because the mean of its divisors is an integer number (10901082454).

Almost surely, 2^21802164907 is an apocalyptic number.

21802164907 is a deficient number, since it is larger than the sum of its proper divisors (1).

21802164907 is an equidigital number, since it uses as much as digits as its factorization.

21802164907 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48384, while the sum is 40.

The spelling of 21802164907 in words is "twenty-one billion, eight hundred two million, one hundred sixty-four thousand, nine hundred seven".