38868991 has 4 divisors (see below), whose sum is σ = 44421712. Its totient is φ = 33316272.

The previous prime is 38868979. The next prime is 38868997. The reversal of 38868991 is 19986883.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 38868991 - 2¹³ = 38860799 is a prime.

It is a super-2 number, since 2×38868991² = 3021596922716162, which contains 22 as substring.

It is the 6235-th Hogben number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (38868997) by changing a digit.

It is a nontrivial repunit in base 6234.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2776350 + ... + 2776363.

It is an arithmetic number, because the mean of its divisors is an integer number (11105428).

Almost surely, 2^38868991 is an apocalyptic number.

38868991 is a deficient number, since it is larger than the sum of its proper divisors (5552721).

38868991 is an equidigital number, since it uses as much as digits as its factorization.

38868991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5552720.

The product of its digits is 746496, while the sum is 52.

The square root of 38868991 is about 6234.5000601492. The cubic root of 38868991 is about 338.7409924848.

The spelling of 38868991 in words is "thirty-eight million, eight hundred sixty-eight thousand, nine hundred ninety-one".