221973845 has 8 divisors (see below), whose sum is σ = 282037464. Its totient is φ = 167133184.

The previous prime is 221973833. The next prime is 221973863. The reversal of 221973845 is 548379122.

It can be written as a sum of positive squares in 4 ways, for example, as 127825636 + 94148209 = 11306^2 + 9703^2 .

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 221973845 - 2¹⁸ = 221711701 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1305644 + ... + 1305813.

It is an arithmetic number, because the mean of its divisors is an integer number (35254683).

Almost surely, 2^221973845 is an apocalyptic number.

It is an amenable number.

221973845 is a deficient number, since it is larger than the sum of its proper divisors (60063619).

221973845 is a wasteful number, since it uses less digits than its factorization.

221973845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2611479.

The product of its digits is 120960, while the sum is 41.

The square root of 221973845 is about 14898.7866955669. The cubic root of 221973845 is about 605.4811144672.

The spelling of 221973845 in words is "two hundred twenty-one million, nine hundred seventy-three thousand, eight hundred forty-five".