201220551 has 32 divisors (see below), whose sum is σ = 360737280. Its totient is φ = 108217728.

The previous prime is 201220529. The next prime is 201220561. The reversal of 201220551 is 155022102.

It is not a de Polignac number, because 201220551 - 2⁵ = 201220519 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201220561) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28101 + ... + 34526.

It is an arithmetic number, because the mean of its divisors is an integer number (11273040).

Almost surely, 2^201220551 is an apocalyptic number.

201220551 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

201220551 is a deficient number, since it is larger than the sum of its proper divisors (159516729).

201220551 is a wasteful number, since it uses less digits than its factorization.

201220551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62660 (or 62654 counting only the distinct ones).

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

The square root of 201220551 is about 14185.2229802707. Note that the first 3 decimals coincide. The cubic root of 201220551 is about 585.9907733834.

Adding to 201220551 its reverse (155022102), we get a palindrome (356242653).

The spelling of 201220551 in words is "two hundred one million, two hundred twenty thousand, five hundred fifty-one".