39890881 has 2 divisors, whose sum is σ = 39890882. Its totient is φ = 39890880.

The previous prime is 39890849. The next prime is 39890933. The reversal of 39890881 is 18809893.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 33177600 + 6713281 = 5760^2 + 2591^2 .

It is a cyclic number.

It is not a de Polignac number, because 39890881 - 2⁵ = 39890849 is a prime.

It is a super-2 number, since 2×39890881² = 3182564773912322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (39890801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19945440 + 19945441.

It is an arithmetic number, because the mean of its divisors is an integer number (19945441).

Almost surely, 2^39890881 is an apocalyptic number.

It is an amenable number.

39890881 is a deficient number, since it is larger than the sum of its proper divisors (1).

39890881 is an equidigital number, since it uses as much as digits as its factorization.

39890881 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 124416, while the sum is 46.

The square root of 39890881 is about 6315.9228146012. The cubic root of 39890881 is about 341.6839213442.

The spelling of 39890881 in words is "thirty-nine million, eight hundred ninety thousand, eight hundred eighty-one".