21373430393 has 12 divisors (see below), whose sum is σ = 24865352820. Its totient is φ = 18318327552.

The previous prime is 21373430383. The next prime is 21373430473. The reversal of 21373430393 is 39303437312.

It can be written as a sum of positive squares in 2 ways, for example, as 4089858304 + 17283572089 = 63952^2 + 131467^2 .

It is not a de Polignac number, because 21373430393 - 2⁸ = 21373430137 is a prime.

It is a super-2 number, since 2×21373430393² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21373430383) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 973505 + ... + 995217.

It is an arithmetic number, because the mean of its divisors is an integer number (2072112735).

Almost surely, 2^21373430393 is an apocalyptic number.

It is an amenable number.

21373430393 is a deficient number, since it is larger than the sum of its proper divisors (3491922427).

21373430393 is a wasteful number, since it uses less digits than its factorization.

21373430393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41816 (or 41809 counting only the distinct ones).

The product of its (nonzero) digits is 122472, while the sum is 38.

The spelling of 21373430393 in words is "twenty-one billion, three hundred seventy-three million, four hundred thirty thousand, three hundred ninety-three".