221887970 has 8 divisors (see below), whose sum is σ = 399398364. Its totient is φ = 88755184.

The previous prime is 221887957. The next prime is 221887979. The reversal of 221887970 is 79788122.

221887970 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 196476289 + 25411681 = 14017^2 + 5041^2 .

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

It is not an unprimeable number, because it can be changed into a prime (221887979) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 11094389 + ... + 11094408.

Almost surely, 2^221887970 is an apocalyptic number.

221887970 is a deficient number, since it is larger than the sum of its proper divisors (177510394).

221887970 is a wasteful number, since it uses less digits than its factorization.

221887970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22188804.

The product of its (nonzero) digits is 112896, while the sum is 44.

The square root of 221887970 is about 14895.9044706926. The cubic root of 221887970 is about 605.4030235892.

The spelling of 221887970 in words is "two hundred twenty-one million, eight hundred eighty-seven thousand, nine hundred seventy".