221838642 has 32 divisors (see below), whose sum is σ = 518923200. Its totient is φ = 70053984.

The previous prime is 221838629. The next prime is 221838649. The reversal of 221838642 is 246838122.

221838642 is a `hidden beast` number, since 2 + 2 + 1 + 8 + 3 + 8 + 642 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 221838597 and 221838606.

It is not an unprimeable number, because it can be changed into a prime (221838649) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 107083 + ... + 109134.

It is an arithmetic number, because the mean of its divisors is an integer number (16216350).

Almost surely, 2^221838642 is an apocalyptic number.

221838642 is an abundant number, since it is smaller than the sum of its proper divisors (297084558).

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

221838642 is a wasteful number, since it uses less digits than its factorization.

221838642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216247 (or 216241 counting only the distinct ones).

The product of its digits is 36864, while the sum is 36.

The square root of 221838642 is about 14894.2486215317. The cubic root of 221838642 is about 605.3581578046.

The spelling of 221838642 in words is "two hundred twenty-one million, eight hundred thirty-eight thousand, six hundred forty-two".