21696195281 has 2 divisors, whose sum is σ = 21696195282. Its totient is φ = 21696195280.

The previous prime is 21696195263. The next prime is 21696195289. The reversal of 21696195281 is 18259169612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15785660881 + 5910534400 = 125641^2 + 76880^2 .

It is a cyclic number.

It is not a de Polignac number, because 21696195281 - 2⁶ = 21696195217 is a prime.

It is a super-2 number, since 2×21696195281² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21696195289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10848097640 + 10848097641.

It is an arithmetic number, because the mean of its divisors is an integer number (10848097641).

Almost surely, 2^21696195281 is an apocalyptic number.

It is an amenable number.

21696195281 is a deficient number, since it is larger than the sum of its proper divisors (1).

21696195281 is an equidigital number, since it uses as much as digits as its factorization.

21696195281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 466560, while the sum is 50.

The spelling of 21696195281 in words is "twenty-one billion, six hundred ninety-six million, one hundred ninety-five thousand, two hundred eighty-one".