206251820 has 48 divisors (see below), whose sum is σ = 459859680. Its totient is φ = 77435904.

The previous prime is 206251817. The next prime is 206251823. The reversal of 206251820 is 28152602.

It is an interprime number because it is at equal distance from previous prime (206251817) and next prime (206251823).

It is a self number, because there is not a number n which added to its sum of digits gives 206251820.

It is not an unprimeable number, because it can be changed into a prime (206251823) 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 15 ways as a sum of consecutive naturals, for example, 185426 + ... + 186534.

It is an arithmetic number, because the mean of its divisors is an integer number (9580410).

Almost surely, 2^206251820 is an apocalyptic number.

206251820 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 206251820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (229929840).

206251820 is an abundant number, since it is smaller than the sum of its proper divisors (253607860).

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

206251820 is a wasteful number, since it uses less digits than its factorization.

206251820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1682 (or 1680 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 26.

The square root of 206251820 is about 14361.4699804721. The cubic root of 206251820 is about 590.8346131128.

The spelling of 206251820 in words is "two hundred six million, two hundred fifty-one thousand, eight hundred twenty".