78639874 has 8 divisors (see below), whose sum is σ = 121148028. Its totient is φ = 38257200.

The previous prime is 78639871. The next prime is 78639877. The reversal of 78639874 is 47893687.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (78639871) and next prime (78639877).

It can be written as a sum of positive squares in 2 ways, for example, as 72846225 + 5793649 = 8535^2 + 2407^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (78639871) 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, 531277 + ... + 531424.

Almost surely, 2^78639874 is an apocalyptic number.

78639874 is a gapful number since it is divisible by the number (74) formed by its first and last digit.

78639874 is a deficient number, since it is larger than the sum of its proper divisors (42508154).

78639874 is a wasteful number, since it uses less digits than its factorization.

78639874 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1062740.

The product of its digits is 2032128, while the sum is 52.

The square root of 78639874 is about 8867.9126066961. The cubic root of 78639874 is about 428.4310481074.

The spelling of 78639874 in words is "seventy-eight million, six hundred thirty-nine thousand, eight hundred seventy-four".