39986643 has 4 divisors (see below), whose sum is σ = 53315528. Its totient is φ = 26657760.

The previous prime is 39986641. The next prime is 39986651. The reversal of 39986643 is 34668993.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34668993 = 3 ⋅11556331.

It is not a de Polignac number, because 39986643 - 2¹ = 39986641 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 39986592 and 39986601.

It is not an unprimeable number, because it can be changed into a prime (39986641) 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, 6664438 + ... + 6664443.

It is an arithmetic number, because the mean of its divisors is an integer number (13328882).

Almost surely, 2^39986643 is an apocalyptic number.

39986643 is a deficient number, since it is larger than the sum of its proper divisors (13328885).

39986643 is a wasteful number, since it uses less digits than its factorization.

39986643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13328884.

The product of its digits is 839808, while the sum is 48.

The square root of 39986643 is about 6323.4992686012. The cubic root of 39986643 is about 341.9571181829.

The spelling of 39986643 in words is "thirty-nine million, nine hundred eighty-six thousand, six hundred forty-three".