21156888941 has 2 divisors, whose sum is σ = 21156888942. Its totient is φ = 21156888940.

The previous prime is 21156888919. The next prime is 21156888983. The reversal of 21156888941 is 14988865112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16416015625 + 4740873316 = 128125^2 + 68854^2 .

It is a cyclic number.

It is not a de Polignac number, because 21156888941 - 2⁶ = 21156888877 is a prime.

It is a super-2 number, since 2×21156888941² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21156888041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10578444470 + 10578444471.

It is an arithmetic number, because the mean of its divisors is an integer number (10578444471).

Almost surely, 2^21156888941 is an apocalyptic number.

It is an amenable number.

21156888941 is a deficient number, since it is larger than the sum of its proper divisors (1).

21156888941 is an equidigital number, since it uses as much as digits as its factorization.

21156888941 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1105920, while the sum is 53.

The spelling of 21156888941 in words is "twenty-one billion, one hundred fifty-six million, eight hundred eighty-eight thousand, nine hundred forty-one".