221743746 has 48 divisors (see below), whose sum is σ = 554770944. Its totient is φ = 62698752.

The previous prime is 221743727. The next prime is 221743747. The reversal of 221743746 is 647347122.

221743746 is a `hidden beast` number, since 2 + 217 + 437 + 4 + 6 = 666.

It is a super-2 number, since 2×221743746² = 98340577780225032, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 221743746.

It is not an unprimeable number, because it can be changed into a prime (221743747) 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 23 ways as a sum of consecutive naturals, for example, 3151 + ... + 21293.

It is an arithmetic number, because the mean of its divisors is an integer number (11557728).

Almost surely, 2^221743746 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221743746, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (277385472).

221743746 is an abundant number, since it is smaller than the sum of its proper divisors (333027198).

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

221743746 is a wasteful number, since it uses less digits than its factorization.

221743746 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18255 (or 18252 counting only the distinct ones).

The product of its digits is 56448, while the sum is 36.

The square root of 221743746 is about 14891.0626215861. The cubic root of 221743746 is about 605.2718273973.

The spelling of 221743746 in words is "two hundred twenty-one million, seven hundred forty-three thousand, seven hundred forty-six".