39916981 has 16 divisors (see below), whose sum is σ = 44392320. Its totient is φ = 35663040.

The previous prime is 39916979. The next prime is 39916991. The reversal of 39916981 is 18961993.

It is a cyclic number.

It is not a de Polignac number, because 39916981 - 2¹ = 39916979 is a prime.

It is a super-2 number, since 2×39916981² = 3186730744308722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39916931) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54091 + ... + 54823.

It is an arithmetic number, because the mean of its divisors is an integer number (2774520).

Almost surely, 2^39916981 is an apocalyptic number.

It is an amenable number.

39916981 is a deficient number, since it is larger than the sum of its proper divisors (4475339).

39916981 is a wasteful number, since it uses less digits than its factorization.

39916981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 876.

The product of its digits is 104976, while the sum is 46.

The square root of 39916981 is about 6317.9886831174. The cubic root of 39916981 is about 341.7584246381.

The spelling of 39916981 in words is "thirty-nine million, nine hundred sixteen thousand, nine hundred eighty-one".