21311657089 has 2 divisors, whose sum is σ = 21311657090. Its totient is φ = 21311657088.

The previous prime is 21311657041. The next prime is 21311657189. The reversal of 21311657089 is 98075611312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21311620225 + 36864 = 145985^2 + 192^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21311657089 is a prime.

It is not a weakly prime, because it can be changed into another prime (21311657039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10655828544 + 10655828545.

It is an arithmetic number, because the mean of its divisors is an integer number (10655828545).

Almost surely, 2^21311657089 is an apocalyptic number.

It is an amenable number.

21311657089 is a deficient number, since it is larger than the sum of its proper divisors (1).

21311657089 is an equidigital number, since it uses as much as digits as its factorization.

21311657089 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90720, while the sum is 43.

The spelling of 21311657089 in words is "twenty-one billion, three hundred eleven million, six hundred fifty-seven thousand, eighty-nine".