38921639 has 4 divisors (see below), whose sum is σ = 38937360. Its totient is φ = 38905920.

The previous prime is 38921621. The next prime is 38921657. The reversal of 38921639 is 93612983.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93612983 = 199 ⋅470417.

It is an interprime number because it is at equal distance from previous prime (38921621) and next prime (38921657).

It is a cyclic number.

It is not a de Polignac number, because 38921639 - 2⁸ = 38921383 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 38921596 and 38921605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (38921689) 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, 3242 + ... + 9399.

It is an arithmetic number, because the mean of its divisors is an integer number (9734340).

Almost surely, 2^38921639 is an apocalyptic number.

38921639 is a deficient number, since it is larger than the sum of its proper divisors (15721).

38921639 is a wasteful number, since it uses less digits than its factorization.

38921639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15720.

The product of its digits is 69984, while the sum is 41.

The square root of 38921639 is about 6238.7209426292. The cubic root of 38921639 is about 338.8938649015.

The spelling of 38921639 in words is "thirty-eight million, nine hundred twenty-one thousand, six hundred thirty-nine".