21110100961 has 2 divisors, whose sum is σ = 21110100962. Its totient is φ = 21110100960.

The previous prime is 21110100929. The next prime is 21110101009. The reversal of 21110100961 is 16900101112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21016010961 + 94090000 = 144969^2 + 9700^2 .

It is a cyclic number.

It is not a de Polignac number, because 21110100961 - 2⁵ = 21110100929 is a prime.

It is a super-2 number, since 2×21110100961² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21110100061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555050480 + 10555050481.

It is an arithmetic number, because the mean of its divisors is an integer number (10555050481).

Almost surely, 2^21110100961 is an apocalyptic number.

It is an amenable number.

21110100961 is a deficient number, since it is larger than the sum of its proper divisors (1).

21110100961 is an equidigital number, since it uses as much as digits as its factorization.

21110100961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 22.

The spelling of 21110100961 in words is "twenty-one billion, one hundred ten million, one hundred thousand, nine hundred sixty-one".