38399991 has 16 divisors (see below), whose sum is σ = 61956864. Its totient is φ = 20651904.

The previous prime is 38399983. The next prime is 38400023. The reversal of 38399991 is 19999383.

It is not a de Polignac number, because 38399991 - 2³ = 38399983 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (38399951) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53425 + ... + 54138.

It is an arithmetic number, because the mean of its divisors is an integer number (3872304).

Almost surely, 2^38399991 is an apocalyptic number.

38399991 is a deficient number, since it is larger than the sum of its proper divisors (23556873).

38399991 is a wasteful number, since it uses less digits than its factorization.

38399991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107590.

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

The square root of 38399991 is about 6196.7726277474. The cubic root of 38399991 is about 337.3730397634.

The spelling of 38399991 in words is "thirty-eight million, three hundred ninety-nine thousand, nine hundred ninety-one".