80777778 has 32 divisors (see below), whose sum is σ = 180066240. Its totient is φ = 24007680.

The previous prime is 80777773. The next prime is 80777821. The reversal of 80777778 is 87777708.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a self number, because there is not a number n which added to its sum of digits gives 80777778.

It is not an unprimeable number, because it can be changed into a prime (80777773) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18903 + ... + 22778.

It is an arithmetic number, because the mean of its divisors is an integer number (5627070).

Almost surely, 2^80777778 is an apocalyptic number.

80777778 is an abundant number, since it is smaller than the sum of its proper divisors (99288462).

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

80777778 is a wasteful number, since it uses less digits than its factorization.

80777778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41722.

The product of its (nonzero) digits is 1075648, while the sum is 51.

The square root of 80777778 is about 8987.6458541712. The cubic root of 80777778 is about 432.2788301954.

The spelling of 80777778 in words is "eighty million, seven hundred seventy-seven thousand, seven hundred seventy-eight".