39929681 has 8 divisors (see below), whose sum is σ = 44112000. Its totient is φ = 35839440.

The previous prime is 39929677. The next prime is 39929693. The reversal of 39929681 is 18692993.

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 39929681 - 2² = 39929677 is a prime.

It is a super-2 number, since 2×39929681² = 3188758849523522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (39929381) 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, 22106 + ... + 23843.

It is an arithmetic number, because the mean of its divisors is an integer number (5514000).

Almost surely, 2^39929681 is an apocalyptic number.

It is an amenable number.

39929681 is a deficient number, since it is larger than the sum of its proper divisors (4182319).

39929681 is a wasteful number, since it uses less digits than its factorization.

39929681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46039.

The product of its digits is 209952, while the sum is 47.

The square root of 39929681 is about 6318.9936698813. The cubic root of 39929681 is about 341.7946654531.

The spelling of 39929681 in words is "thirty-nine million, nine hundred twenty-nine thousand, six hundred eighty-one".