221681448 has 40 divisors (see below), whose sum is σ = 620915130. Its totient is φ = 73893600.

The previous prime is 221681431. The next prime is 221681459. The reversal of 221681448 is 844186122.

221681448 is digitally balanced in base 2, 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 only one way, i.e., 181764324 + 39917124 = 13482^2 + 6318^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 170403 + ... + 171698.

Almost surely, 2^221681448 is an apocalyptic number.

It is an amenable number.

221681448 is an abundant number, since it is smaller than the sum of its proper divisors (399233682).

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

221681448 is a wasteful number, since it uses less digits than its factorization.

221681448 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 342119 (or 342106 counting only the distinct ones).

The product of its digits is 24576, while the sum is 36.

The square root of 221681448 is about 14888.9706830257. The cubic root of 221681448 is about 605.2151392054.

The spelling of 221681448 in words is "two hundred twenty-one million, six hundred eighty-one thousand, four hundred forty-eight".