21004305293 has 2 divisors, whose sum is σ = 21004305294. Its totient is φ = 21004305292.

The previous prime is 21004305251. The next prime is 21004305323. The reversal of 21004305293 is 39250340012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19960886089 + 1043419204 = 141283^2 + 32302^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21004305293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21004305493) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10502152646 + 10502152647.

It is an arithmetic number, because the mean of its divisors is an integer number (10502152647).

Almost surely, 2^21004305293 is an apocalyptic number.

It is an amenable number.

21004305293 is a deficient number, since it is larger than the sum of its proper divisors (1).

21004305293 is an equidigital number, since it uses as much as digits as its factorization.

21004305293 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6480, while the sum is 29.

The spelling of 21004305293 in words is "twenty-one billion, four million, three hundred five thousand, two hundred ninety-three".