39493813 has 4 divisors (see below), whose sum is σ = 39507148. Its totient is φ = 39480480.

The previous prime is 39493793. The next prime is 39493843. The reversal of 39493813 is 31839493.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 9878449 + 29615364 = 3143^2 + 5442^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-39493813 is a prime.

It is a super-2 number, since 2×39493813² = 3119522530557938, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39493843) 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, 6 + ... + 8887.

It is an arithmetic number, because the mean of its divisors is an integer number (9876787).

Almost surely, 2^39493813 is an apocalyptic number.

It is an amenable number.

39493813 is a deficient number, since it is larger than the sum of its proper divisors (13335).

39493813 is an equidigital number, since it uses as much as digits as its factorization.

39493813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13334.

The product of its digits is 69984, while the sum is 40.

The square root of 39493813 is about 6284.4103144209. The cubic root of 39493813 is about 340.5464482670.

The spelling of 39493813 in words is "thirty-nine million, four hundred ninety-three thousand, eight hundred thirteen".