7931993 has 4 divisors (see below), whose sum is σ = 8205540. Its totient is φ = 7658448.

The previous prime is 7931977. The next prime is 7932011. The reversal of 7931993 is 3991397.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3991397 = 23 ⋅173539.

It can be written as a sum of positive squares in 2 ways, for example, as 3717184 + 4214809 = 1928^2 + 2053^2 .

It is a cyclic number.

It is not a de Polignac number, because 7931993 - 2⁴ = 7931977 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 7931993.

It is not an unprimeable number, because it can be changed into a prime (7931923) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 136730 + ... + 136787.

It is an arithmetic number, because the mean of its divisors is an integer number (2051385).

Almost surely, 2^7931993 is an apocalyptic number.

It is an amenable number.

7931993 is a deficient number, since it is larger than the sum of its proper divisors (273547).

7931993 is a wasteful number, since it uses less digits than its factorization.

7931993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 273546.

The product of its digits is 45927, while the sum is 41.

The square root of 7931993 is about 2816.3794133604. The cubic root of 7931993 is about 199.4316614865.

The spelling of 7931993 in words is "seven million, nine hundred thirty-one thousand, nine hundred ninety-three".