39445991 has 4 divisors (see below), whose sum is σ = 42480312. Its totient is φ = 36411672.

The previous prime is 39445963. The next prime is 39446009. The reversal of 39445991 is 19954493.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19954493 = 13 ⋅1534961.

It is a cyclic number.

It is not a de Polignac number, because 39445991 - 2¹⁰ = 39444967 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39445951) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1517141 + ... + 1517166.

It is an arithmetic number, because the mean of its divisors is an integer number (10620078).

Almost surely, 2^39445991 is an apocalyptic number.

39445991 is a deficient number, since it is larger than the sum of its proper divisors (3034321).

39445991 is a wasteful number, since it uses less digits than its factorization.

39445991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3034320.

The product of its digits is 174960, while the sum is 44.

The square root of 39445991 is about 6280.6043499014. The cubic root of 39445991 is about 340.4089398937.

The spelling of 39445991 in words is "thirty-nine million, four hundred forty-five thousand, nine hundred ninety-one".