38390021 has 4 divisors (see below), whose sum is σ = 38489100. Its totient is φ = 38290944.

The previous prime is 38390017. The next prime is 38390039. The reversal of 38390021 is 12009383.

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

It can be written as a sum of positive squares in 2 ways, for example, as 15484225 + 22905796 = 3935^2 + 4786^2 .

It is a cyclic number.

It is not a de Polignac number, because 38390021 - 2² = 38390017 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (38390041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48956 + ... + 49733.

It is an arithmetic number, because the mean of its divisors is an integer number (9622275).

Almost surely, 2^38390021 is an apocalyptic number.

It is an amenable number.

38390021 is a deficient number, since it is larger than the sum of its proper divisors (99079).

38390021 is an equidigital number, since it uses as much as digits as its factorization.

38390021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99078.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 38390021 is about 6195.9681245145. The cubic root of 38390021 is about 337.3438392327.

The spelling of 38390021 in words is "thirty-eight million, three hundred ninety thousand, twenty-one".