21210112010957 has 2 divisors, whose sum is σ = 21210112010958. Its totient is φ = 21210112010956.

The previous prime is 21210112010929. The next prime is 21210112011013. The reversal of 21210112010957 is 75901021101212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18465188728996 + 2744923281961 = 4297114^2 + 1656781^2 .

It is a cyclic number.

It is not a de Polignac number, because 21210112010957 - 2²⁶ = 21210044902093 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21210112010557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605056005478 + 10605056005479.

It is an arithmetic number, because the mean of its divisors is an integer number (10605056005479).

Almost surely, 2^{21210112010957} is an apocalyptic number.

It is an amenable number.

21210112010957 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210112010957 is an equidigital number, since it uses as much as digits as its factorization.

21210112010957 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2520, while the sum is 32.

The spelling of 21210112010957 in words is "twenty-one trillion, two hundred ten billion, one hundred twelve million, ten thousand, nine hundred fifty-seven".