21056022138997 has 2 divisors, whose sum is σ = 21056022138998. Its totient is φ = 21056022138996.

The previous prime is 21056022138973. The next prime is 21056022139027. The reversal of 21056022138997 is 79983122065012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19948362716881 + 1107659422116 = 4466359^2 + 1052454^2 .

It is a cyclic number.

It is not a de Polignac number, because 21056022138997 - 2¹⁹ = 21056021614709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21056022138967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10528011069498 + 10528011069499.

It is an arithmetic number, because the mean of its divisors is an integer number (10528011069499).

Almost surely, 2^{21056022138997} is an apocalyptic number.

It is an amenable number.

21056022138997 is a deficient number, since it is larger than the sum of its proper divisors (1).

21056022138997 is an equidigital number, since it uses as much as digits as its factorization.

21056022138997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3265920, while the sum is 55.

The spelling of 21056022138997 in words is "twenty-one trillion, fifty-six billion, twenty-two million, one hundred thirty-eight thousand, nine hundred ninety-seven".