205891017220 has 24 divisors (see below), whose sum is σ = 494138441664. Its totient is φ = 70591205856.

The previous prime is 205891017193. The next prime is 205891017229. The reversal of 205891017220 is 22710198502.

It is a super-2 number, since 2×205891017220² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 205891017220.

It is not an unprimeable number, because it can be changed into a prime (205891017229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 735324922 + ... + 735325201.

It is an arithmetic number, because the mean of its divisors is an integer number (20589101736).

Almost surely, 2^205891017220 is an apocalyptic number.

205891017220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

205891017220 is an abundant number, since it is smaller than the sum of its proper divisors (288247424444).

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

205891017220 is a wasteful number, since it uses less digits than its factorization.

205891017220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1470650139 (or 1470650137 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 37.

The spelling of 205891017220 in words is "two hundred five billion, eight hundred ninety-one million, seventeen thousand, two hundred twenty".