581491278 has 32 divisors (see below), whose sum is σ = 1310411520. Its totient is φ = 191099160.

The previous prime is 581491259. The next prime is 581491289. The reversal of 581491278 is 872194185.

581491278 is a `hidden beast` number, since 581 + 49 + 1 + 27 + 8 = 666.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 72000 + ... + 79667.

It is an arithmetic number, because the mean of its divisors is an integer number (40950360).

Almost surely, 2^581491278 is an apocalyptic number.

581491278 is an abundant number, since it is smaller than the sum of its proper divisors (728920242).

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

581491278 is a wasteful number, since it uses less digits than its factorization.

581491278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151749 (or 151743 counting only the distinct ones).

The product of its digits is 161280, while the sum is 45.

The square root of 581491278 is about 24114.1302559309. The cubic root of 581491278 is about 834.6692263191.

The spelling of 581491278 in words is "five hundred eighty-one million, four hundred ninety-one thousand, two hundred seventy-eight".