21012301249 has 2 divisors, whose sum is σ = 21012301250. Its totient is φ = 21012301248.

The previous prime is 21012301243. The next prime is 21012301367. The reversal of 21012301249 is 94210321012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17215276849 + 3797024400 = 131207^2 + 61620^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012301249 - 2⁹ = 21012300737 is a prime.

It is not a weakly prime, because it can be changed into another prime (21012301243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506150624 + 10506150625.

It is an arithmetic number, because the mean of its divisors is an integer number (10506150625).

Almost surely, 2^21012301249 is an apocalyptic number.

It is an amenable number.

21012301249 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012301249 is an equidigital number, since it uses as much as digits as its factorization.

21012301249 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 25.

The spelling of 21012301249 in words is "twenty-one billion, twelve million, three hundred one thousand, two hundred forty-nine".