221451870 has 16 divisors (see below), whose sum is σ = 531484560. Its totient is φ = 59053824.

The previous prime is 221451803. The next prime is 221451913. The reversal of 221451870 is 78154122.

It is a Harshad number since it is a multiple of its sum of digits (30), and also a Moran number because the ratio is a prime number: 7381729 = 221451870 / (2 + 2 + 1 + 4 + 5 + 1 + 8 + 7 + 0).

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, 3690835 + ... + 3690894.

It is an arithmetic number, because the mean of its divisors is an integer number (33217785).

Almost surely, 2^221451870 is an apocalyptic number.

221451870 is an abundant number, since it is smaller than the sum of its proper divisors (310032690).

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

221451870 is a wasteful number, since it uses less digits than its factorization.

221451870 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7381739.

The product of its (nonzero) digits is 4480, while the sum is 30.

The square root of 221451870 is about 14881.2590193169. The cubic root of 221451870 is about 605.0061425053.

The spelling of 221451870 in words is "two hundred twenty-one million, four hundred fifty-one thousand, eight hundred seventy".