38905621 has 4 divisors (see below), whose sum is σ = 38931244. Its totient is φ = 38880000.

The previous prime is 38905609. The next prime is 38905631. The reversal of 38905621 is 12650983.

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 20295025 + 18610596 = 4505^2 + 4314^2 .

It is a 5-Lehmer number, since φ(38905621) divides (38905621-1)⁵.

It is a cyclic number.

It is not a de Polignac number, because 38905621 - 2¹¹ = 38903573 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 (38905631) 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, 10380 + ... + 13621.

It is an arithmetic number, because the mean of its divisors is an integer number (9732811).

Almost surely, 2^38905621 is an apocalyptic number.

It is an amenable number.

38905621 is a deficient number, since it is larger than the sum of its proper divisors (25623).

38905621 is a wasteful number, since it uses less digits than its factorization.

38905621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25622.

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 38905621 is about 6237.4370537906. The cubic root of 38905621 is about 338.8473685144.

The spelling of 38905621 in words is "thirty-eight million, nine hundred five thousand, six hundred twenty-one".