221700055551 has 64 divisors (see below), whose sum is σ = 327294309888. Its totient is φ = 132653334528.

The previous prime is 221700055523. The next prime is 221700055553. The reversal of 221700055551 is 155550007122.

It is not a de Polignac number, because 221700055551 - 2³⁵ = 187340317183 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221700055553) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 118365351 + ... + 118367223.

It is an arithmetic number, because the mean of its divisors is an integer number (5113973592).

Almost surely, 2^221700055551 is an apocalyptic number.

221700055551 is a deficient number, since it is larger than the sum of its proper divisors (105594254337).

221700055551 is a wasteful number, since it uses less digits than its factorization.

221700055551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2520.

The product of its (nonzero) digits is 17500, while the sum is 33.

The spelling of 221700055551 in words is "two hundred twenty-one billion, seven hundred million, fifty-five thousand, five hundred fifty-one".