78144778 has 8 divisors (see below), whose sum is σ = 117812772. Its totient is φ = 38873856.

The previous prime is 78144719. The next prime is 78144791. The reversal of 78144778 is 87744187.

It can be written as a sum of positive squares in 2 ways, for example, as 69006249 + 9138529 = 8307^2 + 3023^2 .

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

It is a super-2 number, since 2×78144778² = 12213212657338568, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 98775 + ... + 99562.

Almost surely, 2^78144778 is an apocalyptic number.

78144778 is a deficient number, since it is larger than the sum of its proper divisors (39667994).

78144778 is a wasteful number, since it uses less digits than its factorization.

78144778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198536.

The product of its digits is 351232, while the sum is 46.

The square root of 78144778 is about 8839.9535066651. The cubic root of 78144778 is about 427.5300581900.

The spelling of 78144778 in words is "seventy-eight million, one hundred forty-four thousand, seven hundred seventy-eight".