39928081 has 4 divisors (see below), whose sum is σ = 39952612. Its totient is φ = 39903552.

The previous prime is 39928079. The next prime is 39928111. The reversal of 39928081 is 18082993.

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 16974400 + 22953681 = 4120^2 + 4791^2 .

It is a cyclic number.

It is not a de Polignac number, because 39928081 - 2¹ = 39928079 is a prime.

It is a super-2 number, since 2×39928081² = 3188503304685122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (39928001) 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, 9636 + ... + 13141.

It is an arithmetic number, because the mean of its divisors is an integer number (9988153).

Almost surely, 2^39928081 is an apocalyptic number.

It is an amenable number.

39928081 is a deficient number, since it is larger than the sum of its proper divisors (24531).

39928081 is a wasteful number, since it uses less digits than its factorization.

39928081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24530.

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 39928081 is about 6318.8670661757. The cubic root of 39928081 is about 341.7901001042.

The spelling of 39928081 in words is "thirty-nine million, nine hundred twenty-eight thousand, eighty-one".