83991993 has 4 divisors (see below), whose sum is σ = 111989328. Its totient is φ = 55994660.

The previous prime is 83991979. The next prime is 83991997. The reversal of 83991993 is 39919938.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 83991993 - 2⁸ = 83991737 is a prime.

It is a super-2 number, since 2×83991993² = 14109309776224098, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (83991997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13998663 + ... + 13998668.

It is an arithmetic number, because the mean of its divisors is an integer number (27997332).

Almost surely, 2^83991993 is an apocalyptic number.

It is an amenable number.

83991993 is a deficient number, since it is larger than the sum of its proper divisors (27997335).

83991993 is a wasteful number, since it uses less digits than its factorization.

83991993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27997334.

The product of its digits is 472392, while the sum is 51.

The square root of 83991993 is about 9164.7145618399. The cubic root of 83991993 is about 437.9379981459.

The spelling of 83991993 in words is "eighty-three million, nine hundred ninety-one thousand, nine hundred ninety-three".