39901621 has 4 divisors (see below), whose sum is σ = 39959244. Its totient is φ = 39844000.

The previous prime is 39901607. The next prime is 39901627. The reversal of 39901621 is 12610993.

39901621 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 35533521 + 4368100 = 5961^2 + 2090^2 .

It is a cyclic number.

It is not a de Polignac number, because 39901621 - 2⁷ = 39901493 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39901627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27760 + ... + 29161.

It is an arithmetic number, because the mean of its divisors is an integer number (9989811).

Almost surely, 2^39901621 is an apocalyptic number.

It is an amenable number.

39901621 is a deficient number, since it is larger than the sum of its proper divisors (57623).

39901621 is an equidigital number, since it uses as much as digits as its factorization.

39901621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57622.

The product of its (nonzero) digits is 2916, while the sum is 31.

The square root of 39901621 is about 6316.7729894306. The cubic root of 39901621 is about 341.7145829552.

The spelling of 39901621 in words is "thirty-nine million, nine hundred one thousand, six hundred twenty-one".