78581278 has 4 divisors (see below), whose sum is σ = 117871920. Its totient is φ = 39290638.

The previous prime is 78581263. The next prime is 78581281. The reversal of 78581278 is 87218587.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87218587 = 677 ⋅128831.

It is a super-2 number, since 2×78581278² = 12350034504226568, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19645318 + ... + 19645321.

It is an arithmetic number, because the mean of its divisors is an integer number (29467980).

Almost surely, 2^78581278 is an apocalyptic number.

78581278 is a deficient number, since it is larger than the sum of its proper divisors (39290642).

78581278 is a wasteful number, since it uses less digits than its factorization.

78581278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39290641.

The product of its digits is 250880, while the sum is 46.

The square root of 78581278 is about 8864.6081695696. The cubic root of 78581278 is about 428.3246110790.

The spelling of 78581278 in words is "seventy-eight million, five hundred eighty-one thousand, two hundred seventy-eight".