221540069 has 4 divisors (see below), whose sum is σ = 222092940. Its totient is φ = 220987200.

The previous prime is 221540047. The next prime is 221540089. The reversal of 221540069 is 960045122.

It is a happy number.

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 197402500 + 24137569 = 14050^2 + 4913^2 .

It is a cyclic number.

It is not a de Polignac number, because 221540069 - 2²⁰ = 220491493 is a prime.

It is a super-2 number, since 2×221540069² = 98160004345049522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221540009) 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, 275834 + ... + 276635.

It is an arithmetic number, because the mean of its divisors is an integer number (55523235).

Almost surely, 2^221540069 is an apocalyptic number.

It is an amenable number.

221540069 is a deficient number, since it is larger than the sum of its proper divisors (552871).

221540069 is an equidigital number, since it uses as much as digits as its factorization.

221540069 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 552870.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 221540069 is about 14884.2221496456. Note that the first 3 decimals coincide. The cubic root of 221540069 is about 605.0864516852.

The spelling of 221540069 in words is "two hundred twenty-one million, five hundred forty thousand, sixty-nine".