201555900 has 432 divisors, whose sum is σ = 818947584. Its totient is φ = 40296960.

The previous prime is 201555863. The next prime is 201555901. The reversal of 201555900 is 9555102.

201555900 is a `hidden beast` number, since 20 + 1 + 55 + 590 + 0 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201555901) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 1883647 + ... + 1883753.

It is an arithmetic number, because the mean of its divisors is an integer number (1895712).

Almost surely, 2^201555900 is an apocalyptic number.

201555900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

201555900 is the 11592-nd pentagonal number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 201555900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (409473792).

201555900 is an abundant number, since it is smaller than the sum of its proper divisors (617391684).

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

201555900 is a wasteful number, since it uses less digits than its factorization.

201555900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170 (or 160 counting only the distinct ones).

The product of its (nonzero) digits is 2250, while the sum is 27.

The square root of 201555900 is about 14197.0384235586. The cubic root of 201555900 is about 586.3161250981.

The spelling of 201555900 in words is "two hundred one million, five hundred fifty-five thousand, nine hundred".