21331030393 has 2 divisors, whose sum is σ = 21331030394. Its totient is φ = 21331030392.

The previous prime is 21331030361. The next prime is 21331030433. The reversal of 21331030393 is 39303013312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12917004409 + 8414025984 = 113653^2 + 91728^2 .

It is a cyclic number.

It is not a de Polignac number, because 21331030393 - 2⁵ = 21331030361 is a prime.

It is not a weakly prime, because it can be changed into another prime (21331030493) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10665515196 + 10665515197.

It is an arithmetic number, because the mean of its divisors is an integer number (10665515197).

Almost surely, 2^21331030393 is an apocalyptic number.

It is an amenable number.

21331030393 is a deficient number, since it is larger than the sum of its proper divisors (1).

21331030393 is an equidigital number, since it uses as much as digits as its factorization.

21331030393 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4374, while the sum is 28.

The spelling of 21331030393 in words is "twenty-one billion, three hundred thirty-one million, thirty thousand, three hundred ninety-three".