21566162099 has 2 divisors, whose sum is σ = 21566162100. Its totient is φ = 21566162098.

The previous prime is 21566162077. The next prime is 21566162131. The reversal of 21566162099 is 99026166512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21566162099 - 2³² = 17271194803 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (21566162699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10783081049 + 10783081050.

It is an arithmetic number, because the mean of its divisors is an integer number (10783081050).

Almost surely, 2^21566162099 is an apocalyptic number.

21566162099 is a deficient number, since it is larger than the sum of its proper divisors (1).

21566162099 is an equidigital number, since it uses as much as digits as its factorization.

21566162099 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 349920, while the sum is 47.

The spelling of 21566162099 in words is "twenty-one billion, five hundred sixty-six million, one hundred sixty-two thousand, ninety-nine".