20406693904 has 45 divisors (see below), whose sum is σ = 40182571039. Its totient is φ = 10039638560.

The previous prime is 20406693889. The next prime is 20406693913. The reversal of 20406693904 is 40939660402.

The square root of 20406693904 is 142852.

It is a perfect power (a square), and thus also a powerful number.

It is a super-2 number, since 2×20406693904² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 40569717 + ... + 40570219.

Almost surely, 2^20406693904 is an apocalyptic number.

20406693904 is the 142852-nd square number.

It is an amenable number.

20406693904 is a deficient number, since it is larger than the sum of its proper divisors (19775877135).

20406693904 is an frugal number, since it uses more digits than its factorization.

20406693904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1156 (or 576 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 43.

The spelling of 20406693904 in words is "twenty billion, four hundred six million, six hundred ninety-three thousand, nine hundred four".