38993813 has 2 divisors, whose sum is σ = 38993814. Its totient is φ = 38993812.

The previous prime is 38993807. The next prime is 38993831. The reversal of 38993813 is 31839983.

Together with next prime (38993831) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25170289 + 13823524 = 5017^2 + 3718^2 .

It is a cyclic number.

It is not a de Polignac number, because 38993813 - 2⁴ = 38993797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (38993803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19496906 + 19496907.

It is an arithmetic number, because the mean of its divisors is an integer number (19496907).

Almost surely, 2^38993813 is an apocalyptic number.

It is an amenable number.

38993813 is a deficient number, since it is larger than the sum of its proper divisors (1).

38993813 is an equidigital number, since it uses as much as digits as its factorization.

38993813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 139968, while the sum is 44.

The square root of 38993813 is about 6244.5026223071. The cubic root of 38993813 is about 339.1032105110.

The spelling of 38993813 in words is "thirty-eight million, nine hundred ninety-three thousand, eight hundred thirteen".