38991518 has 4 divisors (see below), whose sum is σ = 58487280. Its totient is φ = 19495758.

The previous prime is 38991499. The next prime is 38991527. The reversal of 38991518 is 81519983.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81519983 = 107 ⋅761869.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9747878 + ... + 9747881.

It is an arithmetic number, because the mean of its divisors is an integer number (14621820).

Almost surely, 2^38991518 is an apocalyptic number.

38991518 is a deficient number, since it is larger than the sum of its proper divisors (19495762).

38991518 is a wasteful number, since it uses less digits than its factorization.

38991518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19495761.

The product of its digits is 77760, while the sum is 44.

The square root of 38991518 is about 6244.3188579700. The cubic root of 38991518 is about 339.0965576852.

The spelling of 38991518 in words is "thirty-eight million, nine hundred ninety-one thousand, five hundred eighteen".