21759198695953 has 2 divisors, whose sum is σ = 21759198695954. Its totient is φ = 21759198695952.

The previous prime is 21759198695921. The next prime is 21759198695959. The reversal of 21759198695953 is 35959689195712.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20586619413504 + 1172579282449 = 4537248^2 + 1082857^2 .

It is a cyclic number.

It is not a de Polignac number, because 21759198695953 - 2⁵ = 21759198695921 is a prime.

It is not a weakly prime, because it can be changed into another prime (21759198695959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10879599347976 + 10879599347977.

It is an arithmetic number, because the mean of its divisors is an integer number (10879599347977).

Almost surely, 2^{21759198695953} is an apocalyptic number.

It is an amenable number.

21759198695953 is a deficient number, since it is larger than the sum of its proper divisors (1).

21759198695953 is an equidigital number, since it uses as much as digits as its factorization.

21759198695953 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1653372000, while the sum is 79.

The spelling of 21759198695953 in words is "twenty-one trillion, seven hundred fifty-nine billion, one hundred ninety-eight million, six hundred ninety-five thousand, nine hundred fifty-three".