78245840 has 20 divisors (see below), whose sum is σ = 181921764. Its totient is φ = 31298304.

The previous prime is 78245837. The next prime is 78245851. The reversal of 78245840 is 4854287.

It can be written as a sum of positive squares in 2 ways, for example, as 37847104 + 40398736 = 6152^2 + 6356^2 .

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

It is a super-2 number, since 2×78245840² = 12244822954611200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78245794 and 78245803.

It is a congruent 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, 488957 + ... + 489116.

Almost surely, 2^78245840 is an apocalyptic number.

It is an amenable number.

78245840 is an abundant number, since it is smaller than the sum of its proper divisors (103675924).

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

78245840 is a wasteful number, since it uses less digits than its factorization.

78245840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 978086 (or 978080 counting only the distinct ones).

The product of its (nonzero) digits is 71680, while the sum is 38.

The square root of 78245840 is about 8845.6678662496. The cubic root of 78245840 is about 427.7142821870.

The spelling of 78245840 in words is "seventy-eight million, two hundred forty-five thousand, eight hundred forty".