993643686 has 40 divisors (see below), whose sum is σ = 2544571920. Its totient is φ = 283897872.

The previous prime is 993643681. The next prime is 993643687. The reversal of 993643686 is 686346399.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (993643681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 436981 + ... + 439248.

It is an arithmetic number, because the mean of its divisors is an integer number (63614298).

Almost surely, 2^993643686 is an apocalyptic number.

993643686 is an abundant number, since it is smaller than the sum of its proper divisors (1550928234).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

993643686 is a wasteful number, since it uses less digits than its factorization.

993643686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 876250 (or 876241 counting only the distinct ones).

The product of its digits is 5038848, while the sum is 54.

The square root of 993643686 is about 31522.1142374683. The cubic root of 993643686 is about 997.8767235546.

The spelling of 993643686 in words is "nine hundred ninety-three million, six hundred forty-three thousand, six hundred eighty-six".