206556378 has 16 divisors (see below), whose sum is σ = 472128960. Its totient is φ = 59016096.

The previous prime is 206556289. The next prime is 206556403. The reversal of 206556378 is 873655602.

It is a Harshad number since it is a multiple of its sum of digits (42), and also a Moran number because the ratio is a prime number: 4918009 = 206556378 / (2 + 0 + 6 + 5 + 5 + 6 + 3 + 7 + 8).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2458963 + ... + 2459046.

It is an arithmetic number, because the mean of its divisors is an integer number (29508060).

Almost surely, 2^206556378 is an apocalyptic number.

206556378 is an abundant number, since it is smaller than the sum of its proper divisors (265572582).

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

206556378 is a wasteful number, since it uses less digits than its factorization.

206556378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4918021.

The product of its (nonzero) digits is 302400, while the sum is 42.

The square root of 206556378 is about 14372.0693708317. The cubic root of 206556378 is about 591.1252851509.

The spelling of 206556378 in words is "two hundred six million, five hundred fifty-six thousand, three hundred seventy-eight".