21000102131249 has 2 divisors, whose sum is σ = 21000102131250. Its totient is φ = 21000102131248.

The previous prime is 21000102131213. The next prime is 21000102131297. The reversal of 21000102131249 is 94213120100012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20773723152400 + 226378978849 = 4557820^2 + 475793^2 .

It is a cyclic number.

It is not a de Polignac number, because 21000102131249 - 2²⁰ = 21000101082673 is a prime.

It is not a weakly prime, because it can be changed into another prime (21000105131249) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500051065624 + 10500051065625.

It is an arithmetic number, because the mean of its divisors is an integer number (10500051065625).

Almost surely, 2^{21000102131249} is an apocalyptic number.

It is an amenable number.

21000102131249 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000102131249 is an equidigital number, since it uses as much as digits as its factorization.

21000102131249 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 26.

The spelling of 21000102131249 in words is "twenty-one trillion, one hundred two million, one hundred thirty-one thousand, two hundred forty-nine".