39979994 has 4 divisors (see below), whose sum is σ = 59969994. Its totient is φ = 19989996.

The previous prime is 39979969. The next prime is 39979997. The reversal of 39979994 is 49997993.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 49997993 = 149 ⋅335557.

It can be written as a sum of positive squares in only one way, i.e., 39853969 + 126025 = 6313^2 + 355^2 .

It is not an unprimeable number, because it can be changed into a prime (39979997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9994997 + ... + 9995000.

Almost surely, 2^39979994 is an apocalyptic number.

39979994 is a deficient number, since it is larger than the sum of its proper divisors (19990000).

39979994 is a wasteful number, since it uses less digits than its factorization.

39979994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19989999.

The product of its digits is 4960116, while the sum is 59.

The square root of 39979994 is about 6322.9735093546. The cubic root of 39979994 is about 341.9381635291.

The spelling of 39979994 in words is "thirty-nine million, nine hundred seventy-nine thousand, nine hundred ninety-four".