201551220 has 96 divisors (see below), whose sum is σ = 675306240. Its totient is φ = 49610880.

The previous prime is 201551177. The next prime is 201551227. The reversal of 201551220 is 22155102.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 201551193 and 201551202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201551227) 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 31 ways as a sum of consecutive naturals, for example, 7336 + ... + 21375.

It is an arithmetic number, because the mean of its divisors is an integer number (7034440).

Almost surely, 2^201551220 is an apocalyptic number.

201551220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

201551220 is an abundant number, since it is smaller than the sum of its proper divisors (473755020).

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

201551220 is a wasteful number, since it uses less digits than its factorization.

201551220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28742 (or 28734 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 201551220 is about 14196.8735994937. The cubic root of 201551220 is about 586.3115871003.

It can be divided in two parts, 2015 and 51220, that added together give a palindrome (53235).

The spelling of 201551220 in words is "two hundred one million, five hundred fifty-one thousand, two hundred twenty".