21939588277 has 2 divisors, whose sum is σ = 21939588278. Its totient is φ = 21939588276.

The previous prime is 21939588257. The next prime is 21939588317. The reversal of 21939588277 is 77288593912.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21609294001 + 330294276 = 147001^2 + 18174^2 .

It is a cyclic number.

It is not a de Polignac number, because 21939588277 - 2⁷ = 21939588149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21939588257) 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, 10969794138 + 10969794139.

It is an arithmetic number, because the mean of its divisors is an integer number (10969794139).

Almost surely, 2^21939588277 is an apocalyptic number.

It is an amenable number.

21939588277 is a deficient number, since it is larger than the sum of its proper divisors (1).

21939588277 is an equidigital number, since it uses as much as digits as its factorization.

21939588277 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15240960, while the sum is 61.

The spelling of 21939588277 in words is "twenty-one billion, nine hundred thirty-nine million, five hundred eighty-eight thousand, two hundred seventy-seven".