21210000039157 has 2 divisors, whose sum is σ = 21210000039158. Its totient is φ = 21210000039156.

The previous prime is 21210000039139. The next prime is 21210000039167. The reversal of 21210000039157 is 75193000001212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21066759741316 + 143240297841 = 4589854^2 + 378471^2 .

It is a cyclic number.

It is not a de Polignac number, because 21210000039157 - 2⁷ = 21210000039029 is a prime.

It is a super-2 number, since 2×21210000039157² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21210000039167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605000019578 + 10605000019579.

It is an arithmetic number, because the mean of its divisors is an integer number (10605000019579).

Almost surely, 2^{21210000039157} is an apocalyptic number.

It is an amenable number.

21210000039157 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210000039157 is an equidigital number, since it uses as much as digits as its factorization.

21210000039157 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3780, while the sum is 31.

The spelling of 21210000039157 in words is "twenty-one trillion, two hundred ten billion, thirty-nine thousand, one hundred fifty-seven".