39945091 has 2 divisors, whose sum is σ = 39945092. Its totient is φ = 39945090.

The previous prime is 39945079. The next prime is 39945119. The reversal of 39945091 is 19054993.

It is a weak prime.

It is an emirp because it is prime and its reverse (19054993) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-39945091 is a prime.

It is a super-2 number, since 2×39945091² = 3191220589996562, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (39945001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19972545 + 19972546.

It is an arithmetic number, because the mean of its divisors is an integer number (19972546).

Almost surely, 2^39945091 is an apocalyptic number.

39945091 is a deficient number, since it is larger than the sum of its proper divisors (1).

39945091 is an equidigital number, since it uses as much as digits as its factorization.

39945091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 43740, while the sum is 40.

The square root of 39945091 is about 6320.2128919839. The cubic root of 39945091 is about 341.8386292267.

The spelling of 39945091 in words is "thirty-nine million, nine hundred forty-five thousand, ninety-one".