78839842 has 4 divisors (see below), whose sum is σ = 118259766. Its totient is φ = 39419920.

The previous prime is 78839807. The next prime is 78839857. The reversal of 78839842 is 24893887.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24893887 = 571 ⋅43597.

It can be written as a sum of positive squares in only one way, i.e., 71216721 + 7623121 = 8439^2 + 2761^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19709959 + ... + 19709962.

Almost surely, 2^78839842 is an apocalyptic number.

78839842 is a deficient number, since it is larger than the sum of its proper divisors (39419924).

78839842 is a wasteful number, since it uses less digits than its factorization.

78839842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39419923.

The product of its digits is 774144, while the sum is 49.

The square root of 78839842 is about 8879.1802549560. The cubic root of 78839842 is about 428.7938834858.

The spelling of 78839842 in words is "seventy-eight million, eight hundred thirty-nine thousand, eight hundred forty-two".