21489597967 has 2 divisors, whose sum is σ = 21489597968. Its totient is φ = 21489597966.

The previous prime is 21489597859. The next prime is 21489597971. The reversal of 21489597967 is 76979598412.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21489597967 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21489598967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10744798983 + 10744798984.

It is an arithmetic number, because the mean of its divisors is an integer number (10744798984).

Almost surely, 2^21489597967 is an apocalyptic number.

21489597967 is a deficient number, since it is larger than the sum of its proper divisors (1).

21489597967 is an equidigital number, since it uses as much as digits as its factorization.

21489597967 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 68584320, while the sum is 67.

The spelling of 21489597967 in words is "twenty-one billion, four hundred eighty-nine million, five hundred ninety-seven thousand, nine hundred sixty-seven".