221240771 has 6 divisors (see below), whose sum is σ = 235020780. Its totient is φ = 208226336.

The previous prime is 221240741. The next prime is 221240777. The reversal of 221240771 is 177042122.

It is not a de Polignac number, because 221240771 - 2¹⁰ = 221239747 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221240771.

It is not an unprimeable number, because it can be changed into a prime (221240777) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 382481 + ... + 383058.

It is an arithmetic number, because the mean of its divisors is an integer number (39170130).

Almost surely, 2^221240771 is an apocalyptic number.

221240771 is a deficient number, since it is larger than the sum of its proper divisors (13780009).

221240771 is an equidigital number, since it uses as much as digits as its factorization.

221240771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 765573 (or 765556 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 26.

The square root of 221240771 is about 14874.1645479671. The cubic root of 221240771 is about 604.8138406822.

Adding to 221240771 its reverse (177042122), we get a palindrome (398282893).

The spelling of 221240771 in words is "two hundred twenty-one million, two hundred forty thousand, seven hundred seventy-one".