221651442 has 24 divisors (see below), whose sum is σ = 482027520. Its totient is φ = 73609560.

The previous prime is 221651431. The next prime is 221651447. The reversal of 221651442 is 244156122.

221651442 is a `hidden beast` number, since 2 + 2 + 1 + 651 + 4 + 4 + 2 = 666.

221651442 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (221651447) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17842 + ... + 27597.

It is an arithmetic number, because the mean of its divisors is an integer number (20084480).

Almost surely, 2^221651442 is an apocalyptic number.

221651442 is an abundant number, since it is smaller than the sum of its proper divisors (260376078).

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

221651442 is a wasteful number, since it uses less digits than its factorization.

221651442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45718 (or 45715 counting only the distinct ones).

The product of its digits is 3840, while the sum is 27.

The square root of 221651442 is about 14887.9629902818. The cubic root of 221651442 is about 605.1878313950.

The spelling of 221651442 in words is "two hundred twenty-one million, six hundred fifty-one thousand, four hundred forty-two".