21204130393 has 2 divisors, whose sum is σ = 21204130394. Its totient is φ = 21204130392.

The previous prime is 21204130369. The next prime is 21204130411. The reversal of 21204130393 is 39303140212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16483478544 + 4720651849 = 128388^2 + 68707^2 .

It is a cyclic number.

It is not a de Polignac number, because 21204130393 - 2¹³ = 21204122201 is a prime.

It is not a weakly prime, because it can be changed into another prime (21204130993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10602065196 + 10602065197.

It is an arithmetic number, because the mean of its divisors is an integer number (10602065197).

Almost surely, 2^21204130393 is an apocalyptic number.

It is an amenable number.

21204130393 is a deficient number, since it is larger than the sum of its proper divisors (1).

21204130393 is an equidigital number, since it uses as much as digits as its factorization.

21204130393 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 28.

The spelling of 21204130393 in words is "twenty-one billion, two hundred four million, one hundred thirty thousand, three hundred ninety-three".