21197103913 has 2 divisors, whose sum is σ = 21197103914. Its totient is φ = 21197103912.

The previous prime is 21197103901. The next prime is 21197103919. The reversal of 21197103913 is 31930179112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14744516329 + 6452587584 = 121427^2 + 80328^2 .

It is a cyclic number.

It is not a de Polignac number, because 21197103913 - 2²⁵ = 21163549481 is a prime.

It is not a weakly prime, because it can be changed into another prime (21197103919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10598551956 + 10598551957.

It is an arithmetic number, because the mean of its divisors is an integer number (10598551957).

Almost surely, 2^21197103913 is an apocalyptic number.

It is an amenable number.

21197103913 is a deficient number, since it is larger than the sum of its proper divisors (1).

21197103913 is an equidigital number, since it uses as much as digits as its factorization.

21197103913 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10206, while the sum is 37.

The spelling of 21197103913 in words is "twenty-one billion, one hundred ninety-seven million, one hundred three thousand, nine hundred thirteen".