206778840 has 64 divisors (see below), whose sum is σ = 623151360. Its totient is φ = 54890880.

The previous prime is 206778833. The next prime is 206778853. The reversal of 206778840 is 48877602.

It is a junction number, because it is equal to n+sod(n) for n = 206778792 and 206778801.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23445 + ... + 31035.

It is an arithmetic number, because the mean of its divisors is an integer number (9736740).

Almost surely, 2^206778840 is an apocalyptic number.

206778840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 206778840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (311575680).

206778840 is an abundant number, since it is smaller than the sum of its proper divisors (416372520).

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

206778840 is a wasteful number, since it uses less digits than its factorization.

206778840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7832 (or 7828 counting only the distinct ones).

The product of its (nonzero) digits is 150528, while the sum is 42.

The square root of 206778840 is about 14379.8066746393. The cubic root of 206778840 is about 591.3374237334.

The spelling of 206778840 in words is "two hundred six million, seven hundred seventy-eight thousand, eight hundred forty".