221251643 has 8 divisors (see below), whose sum is σ = 229759200. Its totient is φ = 212802688.

The previous prime is 221251633. The next prime is 221251649. The reversal of 221251643 is 346152122.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 221251643 - 2¹⁶ = 221186107 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221251649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6878 + ... + 22131.

It is an arithmetic number, because the mean of its divisors is an integer number (28719900).

Almost surely, 2^221251643 is an apocalyptic number.

221251643 is a deficient number, since it is larger than the sum of its proper divisors (8507557).

221251643 is a wasteful number, since it uses less digits than its factorization.

221251643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29301.

The product of its digits is 2880, while the sum is 26.

The square root of 221251643 is about 14874.5300093818. The cubic root of 221251643 is about 604.8237475789.

The spelling of 221251643 in words is "two hundred twenty-one million, two hundred fifty-one thousand, six hundred forty-three".