406688778 has 12 divisors (see below), whose sum is σ = 881159058. Its totient is φ = 135562920.

The previous prime is 406688743. The next prime is 406688801. The reversal of 406688778 is 877886604.

It can be written as a sum of positive squares in only one way, i.e., 344956329 + 61732449 = 18573^2 + 7857^2 .

It is a super-2 number, since 2×406688778² = 330791524302266568, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11296893 + ... + 11296928.

Almost surely, 2^406688778 is an apocalyptic number.

406688778 is an abundant number, since it is smaller than the sum of its proper divisors (474470280).

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

406688778 is a wasteful number, since it uses less digits than its factorization.

406688778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22593829 (or 22593826 counting only the distinct ones).

The product of its (nonzero) digits is 3612672, while the sum is 54.

The square root of 406688778 is about 20166.5261758192. The cubic root of 406688778 is about 740.8905628238.

The spelling of 406688778 in words is "four hundred six million, six hundred eighty-eight thousand, seven hundred seventy-eight".