221995870 has 16 divisors (see below), whose sum is σ = 413372160. Its totient is φ = 85736224.

The previous prime is 221995859. The next prime is 221995889. The reversal of 221995870 is 78599122.

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 7 ways as a sum of consecutive naturals, for example, 382462 + ... + 383041.

It is an arithmetic number, because the mean of its divisors is an integer number (25835760).

Almost surely, 2^221995870 is an apocalyptic number.

221995870 is a deficient number, since it is larger than the sum of its proper divisors (191376290).

221995870 is a wasteful number, since it uses less digits than its factorization.

221995870 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 765539.

The product of its (nonzero) digits is 90720, while the sum is 43.

The square root of 221995870 is about 14899.5258313813. The cubic root of 221995870 is about 605.5011397701.

It can be divided in two parts, 2219 and 95870, that added together give a palindrome (98089).

The spelling of 221995870 in words is "two hundred twenty-one million, nine hundred ninety-five thousand, eight hundred seventy".