39928381 has 8 divisors (see below), whose sum is σ = 40941824. Its totient is φ = 38918880.

The previous prime is 39928379. The next prime is 39928409. The reversal of 39928381 is 18382993.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 39928381 - 2¹ = 39928379 is a prime.

It is a super-2 number, since 2×39928381² = 3188551218562322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39928351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39796 + ... + 40786.

It is an arithmetic number, because the mean of its divisors is an integer number (5117728).

Almost surely, 2^39928381 is an apocalyptic number.

It is an amenable number.

39928381 is a deficient number, since it is larger than the sum of its proper divisors (1013443).

39928381 is an equidigital number, since it uses as much as digits as its factorization.

39928381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1971.

The product of its digits is 93312, while the sum is 43.

The square root of 39928381 is about 6318.8908045637. The cubic root of 39928381 is about 341.7909561164.

The spelling of 39928381 in words is "thirty-nine million, nine hundred twenty-eight thousand, three hundred eighty-one".