221878412 has 12 divisors (see below), whose sum is σ = 443756880. Its totient is φ = 95090736.

The previous prime is 221878387. The next prime is 221878421. The reversal of 221878412 is 214878122.

221878412 is an admirable number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 3962087 + ... + 3962142.

It is an arithmetic number, because the mean of its divisors is an integer number (36979740).

Almost surely, 2^221878412 is an apocalyptic number.

It is an amenable number.

221878412 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

221878412 is a wasteful number, since it uses less digits than its factorization.

221878412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7924240 (or 7924238 counting only the distinct ones).

The product of its digits is 14336, while the sum is 35.

The square root of 221878412 is about 14895.5836407977. The cubic root of 221878412 is about 605.3943307262.

The spelling of 221878412 in words is "two hundred twenty-one million, eight hundred seventy-eight thousand, four hundred twelve".