21697710049 has 2 divisors, whose sum is σ = 21697710050. Its totient is φ = 21697710048.

The previous prime is 21697710017. The next prime is 21697710053. The reversal of 21697710049 is 94001779612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11989155025 + 9708555024 = 109495^2 + 98532^2 .

It is a cyclic number.

It is not a de Polignac number, because 21697710049 - 2⁵ = 21697710017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21697709990 and 21697710008.

It is not a weakly prime, because it can be changed into another prime (21697710949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10848855024 + 10848855025.

It is an arithmetic number, because the mean of its divisors is an integer number (10848855025).

Almost surely, 2^21697710049 is an apocalyptic number.

It is an amenable number.

21697710049 is a deficient number, since it is larger than the sum of its proper divisors (1).

21697710049 is an equidigital number, since it uses as much as digits as its factorization.

21697710049 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 190512, while the sum is 46.

The spelling of 21697710049 in words is "twenty-one billion, six hundred ninety-seven million, seven hundred ten thousand, forty-nine".