38820991 has 8 divisors (see below), whose sum is σ = 42747264. Its totient is φ = 34960920.

The previous prime is 38820961. The next prime is 38821001. The reversal of 38820991 is 19902883.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 38820991 - 2¹¹ = 38818943 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (38820931) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15315 + ... + 17668.

It is an arithmetic number, because the mean of its divisors is an integer number (5343408).

Almost surely, 2^38820991 is an apocalyptic number.

38820991 is a deficient number, since it is larger than the sum of its proper divisors (3926273).

38820991 is a wasteful number, since it uses less digits than its factorization.

38820991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33101.

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 38820991 is about 6230.6493241074. The cubic root of 38820991 is about 338.6014959788.

The spelling of 38820991 in words is "thirty-eight million, eight hundred twenty thousand, nine hundred ninety-one".