398722778 has 8 divisors (see below), whose sum is σ = 598248180. Its totient is φ = 199306720.

The previous prime is 398722757. The next prime is 398722813. The reversal of 398722778 is 877227893.

It can be written as a sum of positive squares in 2 ways, for example, as 345476569 + 53246209 = 18587^2 + 7297^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

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, 17513 + ... + 33228.

Almost surely, 2^398722778 is an apocalyptic number.

398722778 is a deficient number, since it is larger than the sum of its proper divisors (199525402).

398722778 is a wasteful number, since it uses less digits than its factorization.

398722778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54672.

The product of its digits is 2370816, while the sum is 53.

The square root of 398722778 is about 19968.0439202241. The cubic root of 398722778 is about 736.0212425442.

The spelling of 398722778 in words is "three hundred ninety-eight million, seven hundred twenty-two thousand, seven hundred seventy-eight".