221705480 has 64 divisors (see below), whose sum is σ = 521208000. Its totient is φ = 84789504.

The previous prime is 221705467. The next prime is 221705489. The reversal of 221705480 is 84507122.

221705480 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (221705489) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 86051 + ... + 88589.

It is an arithmetic number, because the mean of its divisors is an integer number (8143875).

Almost surely, 2^221705480 is an apocalyptic number.

221705480 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221705480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (260604000).

221705480 is an abundant number, since it is smaller than the sum of its proper divisors (299502520).

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

221705480 is a wasteful number, since it uses less digits than its factorization.

221705480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2646 (or 2642 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 29.

The square root of 221705480 is about 14889.7777014971. Note that the first 4 decimals coincide. The cubic root of 221705480 is about 605.2370084308.

The spelling of 221705480 in words is "two hundred twenty-one million, seven hundred five thousand, four hundred eighty".