21315155963 has 2 divisors, whose sum is σ = 21315155964. Its totient is φ = 21315155962.

The previous prime is 21315155959. The next prime is 21315156001. The reversal of 21315155963 is 36955151312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21315155963 - 2² = 21315155959 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21315155963.

It is not a weakly prime, because it can be changed into another prime (21315154963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10657577981 + 10657577982.

It is an arithmetic number, because the mean of its divisors is an integer number (10657577982).

Almost surely, 2^21315155963 is an apocalyptic number.

21315155963 is a deficient number, since it is larger than the sum of its proper divisors (1).

21315155963 is an equidigital number, since it uses as much as digits as its factorization.

21315155963 is an evil number, because the sum of its binary digits is even.

The product of its digits is 121500, while the sum is 41.

The spelling of 21315155963 in words is "twenty-one billion, three hundred fifteen million, one hundred fifty-five thousand, nine hundred sixty-three".