221978344 has 16 divisors (see below), whose sum is σ = 475668000. Its totient is φ = 95133552.

The previous prime is 221978291. The next prime is 221978357. The reversal of 221978344 is 443879122.

It is a junction number, because it is equal to n+sod(n) for n = 221978297 and 221978306.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1981894 + ... + 1982005.

It is an arithmetic number, because the mean of its divisors is an integer number (29729250).

Almost surely, 2^221978344 is an apocalyptic number.

It is an amenable number.

221978344 is an abundant number, since it is smaller than the sum of its proper divisors (253689656).

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

221978344 is a wasteful number, since it uses less digits than its factorization.

221978344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3963912 (or 3963908 counting only the distinct ones).

The product of its digits is 96768, while the sum is 40.

The square root of 221978344 is about 14898.9376802509. The cubic root of 221978344 is about 605.4852051010.

The spelling of 221978344 in words is "two hundred twenty-one million, nine hundred seventy-eight thousand, three hundred forty-four".