78722778 has 16 divisors (see below), whose sum is σ = 158124096. Its totient is φ = 26127840.

The previous prime is 78722773. The next prime is 78722821. The reversal of 78722778 is 87722787.

It is not an unprimeable number, because it can be changed into a prime (78722773) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26758 + ... + 29553.

It is an arithmetic number, because the mean of its divisors is an integer number (9882756).

Almost surely, 2^78722778 is an apocalyptic number.

78722778 is an abundant number, since it is smaller than the sum of its proper divisors (79401318).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78722778 is a wasteful number, since it uses less digits than its factorization.

78722778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56549.

The product of its digits is 614656, while the sum is 48.

The square root of 78722778 is about 8872.5857561367. The cubic root of 78722778 is about 428.5815492531.

Subtracting 78722778 from its reverse (87722787), we obtain a palindrome (9000009).

The spelling of 78722778 in words is "seventy-eight million, seven hundred twenty-two thousand, seven hundred seventy-eight".