21311925475157 has 2 divisors, whose sum is σ = 21311925475158. Its totient is φ = 21311925475156.

The previous prime is 21311925475133. The next prime is 21311925475277. The reversal of 21311925475157 is 75157452911312.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15632921914801 + 5679003560356 = 3953849^2 + 2383066^2 .

It is a cyclic number.

It is not a de Polignac number, because 21311925475157 - 2²⁴ = 21311908697941 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21311925475099 and 21311925475108.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21311925475657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10655962737578 + 10655962737579.

It is an arithmetic number, because the mean of its divisors is an integer number (10655962737579).

Almost surely, 2^{21311925475157} is an apocalyptic number.

It is an amenable number.

21311925475157 is a deficient number, since it is larger than the sum of its proper divisors (1).

21311925475157 is an equidigital number, since it uses as much as digits as its factorization.

21311925475157 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2646000, while the sum is 53.

The spelling of 21311925475157 in words is "twenty-one trillion, three hundred eleven billion, nine hundred twenty-five million, four hundred seventy-five thousand, one hundred fifty-seven".