221782940 has 48 divisors (see below), whose sum is σ = 479201184. Its totient is φ = 86169600.

The previous prime is 221782933. The next prime is 221782943. The reversal of 221782940 is 49287122.

It is a self number, because there is not a number n which added to its sum of digits gives 221782940.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221782943) 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 15 ways as a sum of consecutive naturals, for example, 251300 + ... + 252180.

It is an arithmetic number, because the mean of its divisors is an integer number (9983358).

Almost surely, 2^221782940 is an apocalyptic number.

221782940 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 221782940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (239600592).

221782940 is an abundant number, since it is smaller than the sum of its proper divisors (257418244).

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

221782940 is a wasteful number, since it uses less digits than its factorization.

221782940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1238 (or 1236 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 35.

The square root of 221782940 is about 14892.3785877206. The cubic root of 221782940 is about 605.3074866164.

The spelling of 221782940 in words is "two hundred twenty-one million, seven hundred eighty-two thousand, nine hundred forty".