221682021 has 16 divisors (see below), whose sum is σ = 323277888. Its totient is φ = 134006400.

The previous prime is 221682011. The next prime is 221682031. The reversal of 221682021 is 120286122.

It is an interprime number because it is at equal distance from previous prime (221682011) and next prime (221682031).

It is not a de Polignac number, because 221682021 - 2⁷ = 221681893 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221681982 and 221682000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221682011) 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, 4641 + ... + 21561.

It is an arithmetic number, because the mean of its divisors is an integer number (20204868).

Almost surely, 2^221682021 is an apocalyptic number.

It is an amenable number.

221682021 is a deficient number, since it is larger than the sum of its proper divisors (101595867).

221682021 is a wasteful number, since it uses less digits than its factorization.

221682021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17332.

The product of its (nonzero) digits is 768, while the sum is 24.

The square root of 221682021 is about 14888.9899254449. The cubic root of 221682021 is about 605.2156606563.

The spelling of 221682021 in words is "two hundred twenty-one million, six hundred eighty-two thousand, twenty-one".