221660340 has 192 divisors, whose sum is σ = 721647360. Its totient is φ = 50319360.

The previous prime is 221660287. The next prime is 221660347. The reversal of 221660340 is 43066122.

It is a self number, because there is not a number n which added to its sum of digits gives 221660340.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221660347) 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 63 ways as a sum of consecutive naturals, for example, 708024 + ... + 708336.

It is an arithmetic number, because the mean of its divisors is an integer number (3758580).

Almost surely, 2^221660340 is an apocalyptic number.

221660340 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 221660340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (360823680).

221660340 is an abundant number, since it is smaller than the sum of its proper divisors (499987020).

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

221660340 is a wasteful number, since it uses less digits than its factorization.

221660340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 402 (or 400 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 24.

The square root of 221660340 is about 14888.2618192991. The cubic root of 221660340 is about 605.1959295290.

The spelling of 221660340 in words is "two hundred twenty-one million, six hundred sixty thousand, three hundred forty".