221878370 has 24 divisors (see below), whose sum is σ = 464587164. Its totient is φ = 76072416.

The previous prime is 221878361. The next prime is 221878379. The reversal of 221878370 is 73878122.

It is an interprime number because it is at equal distance from previous prime (221878361) and next prime (221878379).

It can be written as a sum of positive squares in 2 ways, for example, as 183846481 + 38031889 = 13559^2 + 6167^2 .

It is a super-2 number, since 2×221878370² = 98460022147713800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (221878379) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 225917 + ... + 226896.

Almost surely, 2^221878370 is an apocalyptic number.

221878370 is an abundant number, since it is smaller than the sum of its proper divisors (242708794).

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

221878370 is a wasteful number, since it uses less digits than its factorization.

221878370 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 452834 (or 452827 counting only the distinct ones).

The product of its (nonzero) digits is 37632, while the sum is 38.

The square root of 221878370 is about 14895.5822309838. The cubic root of 221878370 is about 605.3942925272.

The spelling of 221878370 in words is "two hundred twenty-one million, eight hundred seventy-eight thousand, three hundred seventy".