77978628 has 108 divisors (see below), whose sum is σ = 244066368. Its totient is φ = 20554560.

The previous prime is 77978627. The next prime is 77978633. The reversal of 77978628 is 82687977.

77978628 is a `hidden beast` number, since 7 + 7 + 9 + 7 + 8 + 628 = 666.

It is not an unprimeable number, because it can be changed into a prime (77978627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 41673 + ... + 43503.

Almost surely, 2^77978628 is an apocalyptic number.

77978628 is a gapful number since it is divisible by the number (78) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77978628, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (122033184).

77978628 is an abundant number, since it is smaller than the sum of its proper divisors (166087740).

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

77978628 is a wasteful number, since it uses less digits than its factorization.

77978628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1874 (or 1856 counting only the distinct ones).

The product of its digits is 2370816, while the sum is 54.

The square root of 77978628 is about 8830.5508321961. The cubic root of 77978628 is about 427.2268409891.

It can be divided in two parts, 77978 and 628, that added together give a triangular number (78606 = T₃₉₆).

The spelling of 77978628 in words is "seventy-seven million, nine hundred seventy-eight thousand, six hundred twenty-eight".