21939992895757 has 2 divisors, whose sum is σ = 21939992895758. Its totient is φ = 21939992895756.

The previous prime is 21939992895719. The next prime is 21939992895809. The reversal of 21939992895757 is 75759829993912.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19905749635396 + 2034243260361 = 4461586^2 + 1426269^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21939992895757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21939992895257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10969996447878 + 10969996447879.

It is an arithmetic number, because the mean of its divisors is an integer number (10969996447879).

Almost surely, 2^{21939992895757} is an apocalyptic number.

It is an amenable number.

21939992895757 is a deficient number, since it is larger than the sum of its proper divisors (1).

21939992895757 is an equidigital number, since it uses as much as digits as its factorization.

21939992895757 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6944162400, while the sum is 85.

The spelling of 21939992895757 in words is "twenty-one trillion, nine hundred thirty-nine billion, nine hundred ninety-two million, eight hundred ninety-five thousand, seven hundred fifty-seven".