39921005 has 4 divisors (see below), whose sum is σ = 47905212. Its totient is φ = 31936800.

The previous prime is 39920987. The next prime is 39921017. The reversal of 39921005 is 50012993.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50012993 = 167 ⋅299479.

It can be written as a sum of positive squares in 2 ways, for example, as 8773444 + 31147561 = 2962^2 + 5581^2 .

It is not a de Polignac number, because 39921005 - 2⁶ = 39920941 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3992096 + ... + 3992105.

It is an arithmetic number, because the mean of its divisors is an integer number (11976303).

Almost surely, 2^39921005 is an apocalyptic number.

It is an amenable number.

39921005 is a deficient number, since it is larger than the sum of its proper divisors (7984207).

39921005 is an equidigital number, since it uses as much as digits as its factorization.

39921005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7984206.

The product of its (nonzero) digits is 2430, while the sum is 29.

The square root of 39921005 is about 6318.3071308698. The cubic root of 39921005 is about 341.7699083864.

Adding to 39921005 its reverse (50012993), we get a palindrome (89933998).

The spelling of 39921005 in words is "thirty-nine million, nine hundred twenty-one thousand, five".