21516902863 has 2 divisors, whose sum is σ = 21516902864. Its totient is φ = 21516902862.

The previous prime is 21516902851. The next prime is 21516902917. The reversal of 21516902863 is 36820961512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21516902863 - 2¹³ = 21516894671 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21516902833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10758451431 + 10758451432.

It is an arithmetic number, because the mean of its divisors is an integer number (10758451432).

Almost surely, 2^21516902863 is an apocalyptic number.

21516902863 is a deficient number, since it is larger than the sum of its proper divisors (1).

21516902863 is an equidigital number, since it uses as much as digits as its factorization.

21516902863 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 155520, while the sum is 43.

The spelling of 21516902863 in words is "twenty-one billion, five hundred sixteen million, nine hundred two thousand, eight hundred sixty-three".