11993708421 has 16 divisors (see below), whose sum is σ = 17794198720. Its totient is φ = 7984221840.

The previous prime is 11993708417. The next prime is 11993708473. The reversal of 11993708421 is 12480739911.

11993708421 is a `hidden beast` number, since 1 + 199 + 37 + 0 + 8 + 421 = 666.

It is not a de Polignac number, because 11993708421 - 2² = 11993708417 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11993708491) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 302770 + ... + 340083.

It is an arithmetic number, because the mean of its divisors is an integer number (1112137420).

Almost surely, 2^11993708421 is an apocalyptic number.

It is an amenable number.

11993708421 is a deficient number, since it is larger than the sum of its proper divisors (5800490299).

11993708421 is an equidigital number, since it uses as much as digits as its factorization.

11993708421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 643553 (or 643547 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 45.

The spelling of 11993708421 in words is "eleven billion, nine hundred ninety-three million, seven hundred eight thousand, four hundred twenty-one".