39906909 has 24 divisors (see below), whose sum is σ = 68744832. Its totient is φ = 21811680.

The previous prime is 39906907. The next prime is 39906931. The reversal of 39906909 is 90960993.

It is not a de Polignac number, because 39906909 - 2¹ = 39906907 is a prime.

It is a super-2 number, since 2×39906909² = 3185122771868562, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39906907) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12322 + ... + 15219.

It is an arithmetic number, because the mean of its divisors is an integer number (2864368).

Almost surely, 2^39906909 is an apocalyptic number.

It is an amenable number.

39906909 is a deficient number, since it is larger than the sum of its proper divisors (28837923).

39906909 is a wasteful number, since it uses less digits than its factorization.

39906909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27577 (or 27574 counting only the distinct ones).

The product of its (nonzero) digits is 118098, while the sum is 45.

The square root of 39906909 is about 6317.1915437162. The cubic root of 39906909 is about 341.7296776377.

The spelling of 39906909 in words is "thirty-nine million, nine hundred six thousand, nine hundred nine".