221668734 has 64 divisors (see below), whose sum is σ = 517625856. Its totient is φ = 61979904.

The previous prime is 221668703. The next prime is 221668747. The reversal of 221668734 is 437866122.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 221668692 and 221668701.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 603819 + ... + 604185.

It is an arithmetic number, because the mean of its divisors is an integer number (8087904).

Almost surely, 2^221668734 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221668734, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (258812928).

221668734 is an abundant number, since it is smaller than the sum of its proper divisors (295957122).

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

221668734 is a wasteful number, since it uses less digits than its factorization.

221668734 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 649.

The product of its digits is 96768, while the sum is 39.

The square root of 221668734 is about 14888.5437165627. The cubic root of 221668734 is about 605.2035687704.

The spelling of 221668734 in words is "two hundred twenty-one million, six hundred sixty-eight thousand, seven hundred thirty-four".