78245581 has 6 divisors (see below), whose sum is σ = 80852046. Its totient is φ = 75720600.

The previous prime is 78245579. The next prime is 78245593. The reversal of 78245581 is 18554287.

It can be written as a sum of positive squares in only one way, i.e., 78057225 + 188356 = 8835^2 + 434^2 .

It is not a de Polignac number, because 78245581 - 2¹ = 78245579 is a prime.

It is a super-2 number, since 2×78245581² = 12244741892055122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78245281) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 39750 + ... + 41671.

It is an arithmetic number, because the mean of its divisors is an integer number (13475341).

Almost surely, 2^78245581 is an apocalyptic number.

It is an amenable number.

78245581 is a deficient number, since it is larger than the sum of its proper divisors (2606465).

78245581 is an equidigital number, since it uses as much as digits as its factorization.

78245581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81483 (or 81452 counting only the distinct ones).

The product of its digits is 89600, while the sum is 40.

The square root of 78245581 is about 8845.6532263027. The cubic root of 78245581 is about 427.7138102636.

The spelling of 78245581 in words is "seventy-eight million, two hundred forty-five thousand, five hundred eighty-one".