21010012099957 has 2 divisors, whose sum is σ = 21010012099958. Its totient is φ = 21010012099956.

The previous prime is 21010012099939. The next prime is 21010012100047. The reversal of 21010012099957 is 75999021001012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20386660795281 + 623351304676 = 4515159^2 + 789526^2 .

It is a cyclic number.

It is not a de Polignac number, because 21010012099957 - 2²⁷ = 21009877882229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21010012099357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505006049978 + 10505006049979.

It is an arithmetic number, because the mean of its divisors is an integer number (10505006049979).

Almost surely, 2^{21010012099957} is an apocalyptic number.

It is an amenable number.

21010012099957 is a deficient number, since it is larger than the sum of its proper divisors (1).

21010012099957 is an equidigital number, since it uses as much as digits as its factorization.

21010012099957 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 102060, while the sum is 46.

The spelling of 21010012099957 in words is "twenty-one trillion, ten billion, twelve million, ninety-nine thousand, nine hundred fifty-seven".