221055840 has 72 divisors (see below), whose sum is σ = 754357968. Its totient is φ = 58947840.

The previous prime is 221055833. The next prime is 221055841. The reversal of 221055840 is 48550122.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (72).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221055841) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 75316 + ... + 78195.

It is an arithmetic number, because the mean of its divisors is an integer number (10477194).

Almost surely, 2^221055840 is an apocalyptic number.

221055840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221055840 is an abundant number, since it is smaller than the sum of its proper divisors (533302128).

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

221055840 is a wasteful number, since it uses less digits than its factorization.

221055840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153532 (or 153521 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 27.

The square root of 221055840 is about 14867.9467311394. The cubic root of 221055840 is about 604.6452762016.

The spelling of 221055840 in words is "two hundred twenty-one million, fifty-five thousand, eight hundred forty".