21334056637 has 2 divisors, whose sum is σ = 21334056638. Its totient is φ = 21334056636.

The previous prime is 21334056607. The next prime is 21334056659. The reversal of 21334056637 is 73665043312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20434416601 + 899640036 = 142949^2 + 29994^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21334056637 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21334056637.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21334056607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10667028318 + 10667028319.

It is an arithmetic number, because the mean of its divisors is an integer number (10667028319).

Almost surely, 2^21334056637 is an apocalyptic number.

It is an amenable number.

21334056637 is a deficient number, since it is larger than the sum of its proper divisors (1).

21334056637 is an equidigital number, since it uses as much as digits as its factorization.

21334056637 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 272160, while the sum is 40.

Adding to 21334056637 its reverse (73665043312), we get a palindrome (94999099949).

The spelling of 21334056637 in words is "twenty-one billion, three hundred thirty-four million, fifty-six thousand, six hundred thirty-seven".