39945081 has 16 divisors (see below), whose sum is σ = 59977728. Its totient is φ = 23427600.

The previous prime is 39945079. The next prime is 39945091. The reversal of 39945081 is 18054993.

It is not a de Polignac number, because 39945081 - 2¹ = 39945079 is a prime.

It is a super-2 number, since 2×39945081² = 3191218992193122, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (39945001) 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, 18501 + ... + 20546.

It is an arithmetic number, because the mean of its divisors is an integer number (3748608).

Almost surely, 2^39945081 is an apocalyptic number.

39945081 is a gapful number since it is divisible by the number (31) formed by its first and last digit.

It is an amenable number.

39945081 is a deficient number, since it is larger than the sum of its proper divisors (20032647).

39945081 is a wasteful number, since it uses less digits than its factorization.

39945081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39092.

The product of its (nonzero) digits is 38880, while the sum is 39.

The square root of 39945081 is about 6320.2121008713. The cubic root of 39945081 is about 341.8386007010.

The spelling of 39945081 in words is "thirty-nine million, nine hundred forty-five thousand, eighty-one".