221826985 has 4 divisors (see below), whose sum is σ = 266192388. Its totient is φ = 177461584.

The previous prime is 221826977. The next prime is 221826989. The reversal of 221826985 is 589628122.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 132411049 + 89415936 = 11507^2 + 9456^2 .

It is a cyclic number.

It is not a de Polignac number, because 221826985 - 2³ = 221826977 is a prime.

It is a super-2 number, since 2×221826985² = 98414422548380450, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221826989) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22182694 + ... + 22182703.

It is an arithmetic number, because the mean of its divisors is an integer number (66548097).

Almost surely, 2^221826985 is an apocalyptic number.

It is an amenable number.

221826985 is a deficient number, since it is larger than the sum of its proper divisors (44365403).

221826985 is an equidigital number, since it uses as much as digits as its factorization.

221826985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44365402.

The product of its digits is 138240, while the sum is 43.

The square root of 221826985 is about 14893.8572908431. The cubic root of 221826985 is about 605.3475543263.

The spelling of 221826985 in words is "two hundred twenty-one million, eight hundred twenty-six thousand, nine hundred eighty-five".