77823939 has 4 divisors (see below), whose sum is σ = 103765256. Its totient is φ = 51882624.

The previous prime is 77823931. The next prime is 77823947. The reversal of 77823939 is 93932877.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93932877 = 3 ⋅31310959.

It is an interprime number because it is at equal distance from previous prime (77823931) and next prime (77823947).

It is not a de Polignac number, because 77823939 - 2³ = 77823931 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77823931) 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, 12970654 + ... + 12970659.

It is an arithmetic number, because the mean of its divisors is an integer number (25941314).

Almost surely, 2^77823939 is an apocalyptic number.

77823939 is a deficient number, since it is larger than the sum of its proper divisors (25941317).

77823939 is a wasteful number, since it uses less digits than its factorization.

77823939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25941316.

The product of its digits is 571536, while the sum is 48.

The square root of 77823939 is about 8821.7877439893. The cubic root of 77823939 is about 426.9441522463.

The spelling of 77823939 in words is "seventy-seven million, eight hundred twenty-three thousand, nine hundred thirty-nine".