398126778 has 32 divisors (see below), whose sum is σ = 927179136. Its totient is φ = 111603648.

The previous prime is 398126759. The next prime is 398126789. The reversal of 398126778 is 877621893.

It is a super-2 number, since 2×398126778² = 317009862721322568, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 398126778.

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, 87201 + ... + 91652.

It is an arithmetic number, because the mean of its divisors is an integer number (28974348).

Almost surely, 2^398126778 is an apocalyptic number.

398126778 is an abundant number, since it is smaller than the sum of its proper divisors (529052358).

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

398126778 is a wasteful number, since it uses less digits than its factorization.

398126778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178918.

The product of its digits is 1016064, while the sum is 51.

The square root of 398126778 is about 19953.1144937326. The cubic root of 398126778 is about 735.6543314667.

The spelling of 398126778 in words is "three hundred ninety-eight million, one hundred twenty-six thousand, seven hundred seventy-eight".