221384642 has 16 divisors (see below), whose sum is σ = 351899640. Its totient is φ = 104095488.

The previous prime is 221384633. The next prime is 221384651. The reversal of 221384642 is 246483122.

It is a Cunningham number, because it is equal to 14879²+1.

It is an interprime number because it is at equal distance from previous prime (221384633) and next prime (221384651).

It can be written as a sum of positive squares in 4 ways, for example, as 172370641 + 49014001 = 13129^2 + 7001^2 .

It is a super-2 number, since 2×221384642² = 98022319426936328, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 221384599 and 221384608.

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 7 ways as a sum of consecutive naturals, for example, 62084 + ... + 65552.

Almost surely, 2^221384642 is an apocalyptic number.

221384642 is a deficient number, since it is larger than the sum of its proper divisors (130514998).

221384642 is a wasteful number, since it uses less digits than its factorization.

221384642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5365.

The product of its digits is 18432, while the sum is 32.

The square root of 221384642 is about 14879.0000336044. Note that the first 4 decimals coincide. The cubic root of 221384642 is about 604.9449140474.

The spelling of 221384642 in words is "two hundred twenty-one million, three hundred eighty-four thousand, six hundred forty-two".