84128780 has 12 divisors (see below), whose sum is σ = 176670480. Its totient is φ = 33651504.

The previous prime is 84128773. The next prime is 84128791. The reversal of 84128780 is 8782148.

It is a happy number.

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, 2103200 + ... + 2103239.

It is an arithmetic number, because the mean of its divisors is an integer number (14722540).

Almost surely, 2^84128780 is an apocalyptic number.

It is an amenable number.

84128780 is an abundant number, since it is smaller than the sum of its proper divisors (92541700).

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

84128780 is a wasteful number, since it uses less digits than its factorization.

84128780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4206448 (or 4206446 counting only the distinct ones).

The product of its (nonzero) digits is 28672, while the sum is 38.

The square root of 84128780 is about 9172.1742242502. The cubic root of 84128780 is about 438.1756070447.

The spelling of 84128780 in words is "eighty-four million, one hundred twenty-eight thousand, seven hundred eighty".