38387921 has 16 divisors (see below), whose sum is σ = 47755008. Its totient is φ = 30316800.

The previous prime is 38387903. The next prime is 38387927. The reversal of 38387921 is 12978383.

It is a cyclic number.

It is not a de Polignac number, because 38387921 - 2⁶ = 38387857 is a prime.

It is a super-4 number, since 4×38387921⁴ (a number of 31 digits) contains 4444 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (38387927) 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, 5465 + ... + 10326.

It is an arithmetic number, because the mean of its divisors is an integer number (2984688).

Almost surely, 2^38387921 is an apocalyptic number.

It is an amenable number.

38387921 is a deficient number, since it is larger than the sum of its proper divisors (9367087).

38387921 is a wasteful number, since it uses less digits than its factorization.

38387921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15832.

The product of its digits is 72576, while the sum is 41.

The square root of 38387921 is about 6195.7986571547. The cubic root of 38387921 is about 337.3376880250.

The spelling of 38387921 in words is "thirty-eight million, three hundred eighty-seven thousand, nine hundred twenty-one".