21431064797 has 2 divisors, whose sum is σ = 21431064798. Its totient is φ = 21431064796.

The previous prime is 21431064761. The next prime is 21431064829. The reversal of 21431064797 is 79746013412.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15105884836 + 6325179961 = 122906^2 + 79531^2 .

It is a cyclic number.

It is not a de Polignac number, because 21431064797 - 2²⁰ = 21430016221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21431067797) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10715532398 + 10715532399.

It is an arithmetic number, because the mean of its divisors is an integer number (10715532399).

Almost surely, 2^21431064797 is an apocalyptic number.

It is an amenable number.

21431064797 is a deficient number, since it is larger than the sum of its proper divisors (1).

21431064797 is an equidigital number, since it uses as much as digits as its factorization.

21431064797 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 254016, while the sum is 44.

The spelling of 21431064797 in words is "twenty-one billion, four hundred thirty-one million, sixty-four thousand, seven hundred ninety-seven".