77428080 has 120 divisors (see below), whose sum is σ = 268494720. Its totient is φ = 19975680.

The previous prime is 77428073. The next prime is 77428121. The reversal of 77428080 is 8082477.

It is a tau number, because it is divible by the number of its divisors (120).

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20586 + ... + 24054.

It is an arithmetic number, because the mean of its divisors is an integer number (2237456).

Almost surely, 2^77428080 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77428080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (134247360).

77428080 is an abundant number, since it is smaller than the sum of its proper divisors (191066640).

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

77428080 is a wasteful number, since it uses less digits than its factorization.

77428080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3519 (or 3510 counting only the distinct ones).

The product of its (nonzero) digits is 25088, while the sum is 36.

The square root of 77428080 is about 8799.3227012083. The cubic root of 77428080 is about 426.2190237865.

The spelling of 77428080 in words is "seventy-seven million, four hundred twenty-eight thousand, eighty".