39881309 has 4 divisors (see below), whose sum is σ = 42949116. Its totient is φ = 36813504.

The previous prime is 39881299. The next prime is 39881311. The reversal of 39881309 is 90318893.

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 21132409 + 18748900 = 4597^2 + 4330^2 .

It is not a de Polignac number, because 39881309 - 2¹² = 39877213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39881329) 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 3 ways as a sum of consecutive naturals, for example, 1533884 + ... + 1533909.

It is an arithmetic number, because the mean of its divisors is an integer number (10737279).

Almost surely, 2^39881309 is an apocalyptic number.

It is an amenable number.

39881309 is a deficient number, since it is larger than the sum of its proper divisors (3067807).

39881309 is a wasteful number, since it uses less digits than its factorization.

39881309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3067806.

The product of its (nonzero) digits is 46656, while the sum is 41.

The square root of 39881309 is about 6315.1650018032. The cubic root of 39881309 is about 341.6565896162.

The spelling of 39881309 in words is "thirty-nine million, eight hundred eighty-one thousand, three hundred nine".