39947799 has 4 divisors (see below), whose sum is σ = 53263736. Its totient is φ = 26631864.

The previous prime is 39947777. The next prime is 39947813. The reversal of 39947799 is 99774993.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 39947799 - 2⁹ = 39947287 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 (39947749) 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, 6657964 + ... + 6657969.

It is an arithmetic number, because the mean of its divisors is an integer number (13315934).

Almost surely, 2^39947799 is an apocalyptic number.

39947799 is a deficient number, since it is larger than the sum of its proper divisors (13315937).

39947799 is a wasteful number, since it uses less digits than its factorization.

39947799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13315936.

The product of its digits is 3857868, while the sum is 57.

The square root of 39947799 is about 6320.4271216430. The cubic root of 39947799 is about 341.8463538145.

The spelling of 39947799 in words is "thirty-nine million, nine hundred forty-seven thousand, seven hundred ninety-nine".