206550021520 has 40 divisors (see below), whose sum is σ = 495720057600. Its totient is φ = 79954846080.

The previous prime is 206550021499. The next prime is 206550021521. The reversal of 206550021520 is 25120055602.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×206550021520² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (206550021521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41640670 + ... + 41645629.

It is an arithmetic number, because the mean of its divisors is an integer number (12393001440).

Almost surely, 2^206550021520 is an apocalyptic number.

206550021520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

206550021520 is an abundant number, since it is smaller than the sum of its proper divisors (289170036080).

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

206550021520 is a wasteful number, since it uses less digits than its factorization.

206550021520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83286343 (or 83286337 counting only the distinct ones).

The product of its (nonzero) digits is 6000, while the sum is 28.

The spelling of 206550021520 in words is "two hundred six billion, five hundred fifty million, twenty-one thousand, five hundred twenty".