39961881 has 6 divisors (see below), whose sum is σ = 57722730. Its totient is φ = 26641248.

The previous prime is 39961877. The next prime is 39961903. The reversal of 39961881 is 18816993.

It can be written as a sum of positive squares in only one way, i.e., 37711881 + 2250000 = 6141^2 + 1500^2 .

It is not a de Polignac number, because 39961881 - 2² = 39961877 is a prime.

It is a super-2 number, since 2×39961881² = 3193903866116322, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (39961871) 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 5 ways as a sum of consecutive naturals, for example, 2220096 + ... + 2220113.

It is an arithmetic number, because the mean of its divisors is an integer number (9620455).

Almost surely, 2^39961881 is an apocalyptic number.

It is an amenable number.

39961881 is a deficient number, since it is larger than the sum of its proper divisors (17760849).

39961881 is a wasteful number, since it uses less digits than its factorization.

39961881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4440215 (or 4440212 counting only the distinct ones).

The product of its digits is 93312, while the sum is 45.

The square root of 39961881 is about 6321.5410304767. The cubic root of 39961881 is about 341.8865171856.

The spelling of 39961881 in words is "thirty-nine million, nine hundred sixty-one thousand, eight hundred eighty-one".