38891391 has 32 divisors (see below), whose sum is σ = 66748416. Its totient is φ = 19548000.

The previous prime is 38891389. The next prime is 38891399. The reversal of 38891391 is 19319883.

It is a happy number.

It is not a de Polignac number, because 38891391 - 2¹ = 38891389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (38891399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4446 + ... + 9876.

It is an arithmetic number, because the mean of its divisors is an integer number (2085888).

Almost surely, 2^38891391 is an apocalyptic number.

38891391 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

38891391 is a deficient number, since it is larger than the sum of its proper divisors (27857025).

38891391 is a wasteful number, since it uses less digits than its factorization.

38891391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5483.

The product of its digits is 46656, while the sum is 42.

The square root of 38891391 is about 6236.2962565933. The cubic root of 38891391 is about 338.8060515537.

The spelling of 38891391 in words is "thirty-eight million, eight hundred ninety-one thousand, three hundred ninety-one".