206778020 has 36 divisors (see below), whose sum is σ = 438467484. Its totient is φ = 81910080.

The previous prime is 206778001. The next prime is 206778023. The reversal of 206778020 is 20877602.

It can be written as a sum of positive squares in 2 ways, for example, as 27646564 + 179131456 = 5258^2 + 13384^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206778023) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 865061 + ... + 865299.

Almost surely, 2^206778020 is an apocalyptic number.

206778020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

206778020 is an abundant number, since it is smaller than the sum of its proper divisors (231689464).

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

206778020 is a wasteful number, since it uses less digits than its factorization.

206778020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 668 (or 427 counting only the distinct ones).

The product of its (nonzero) digits is 9408, while the sum is 32.

The square root of 206778020 is about 14379.7781624057. The cubic root of 206778020 is about 591.3366420652.

The spelling of 206778020 in words is "two hundred six million, seven hundred seventy-eight thousand, twenty".