78420880 has 20 divisors (see below), whose sum is σ = 182328732. Its totient is φ = 31368320.

The previous prime is 78420857. The next prime is 78420889. The reversal of 78420880 is 8802487.

It can be written as a sum of positive squares in 2 ways, for example, as 17205904 + 61214976 = 4148^2 + 7824^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×78420880² = 12299668839948800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78420889) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 490051 + ... + 490210.

Almost surely, 2^78420880 is an apocalyptic number.

It is an amenable number.

78420880 is an abundant number, since it is smaller than the sum of its proper divisors (103907852).

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

78420880 is a wasteful number, since it uses less digits than its factorization.

78420880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 980274 (or 980268 counting only the distinct ones).

The product of its (nonzero) digits is 28672, while the sum is 37.

The square root of 78420880 is about 8855.5564477903. The cubic root of 78420880 is about 428.0329843273.

The spelling of 78420880 in words is "seventy-eight million, four hundred twenty thousand, eight hundred eighty".