993318855921 has 48 divisors (see below), whose sum is σ = 1675086686208. Its totient is φ = 555390108000.

The previous prime is 993318855917. The next prime is 993318855937. The reversal of 993318855921 is 129558813399.

993318855921 is a `hidden beast` number, since 9 + 9 + 3 + 31 + 8 + 8 + 5 + 592 + 1 = 666.

It is not a de Polignac number, because 993318855921 - 2² = 993318855917 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (993318853921) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 11953606 + ... + 12036416.

It is an arithmetic number, because the mean of its divisors is an integer number (34897639296).

Almost surely, 2^993318855921 is an apocalyptic number.

It is an amenable number.

993318855921 is a deficient number, since it is larger than the sum of its proper divisors (681767830287).

993318855921 is a wasteful number, since it uses less digits than its factorization.

993318855921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86922 (or 86919 counting only the distinct ones).

The product of its digits is 20995200, while the sum is 63.

The spelling of 993318855921 in words is "nine hundred ninety-three billion, three hundred eighteen million, eight hundred fifty-five thousand, nine hundred twenty-one".