221504013 has 24 divisors (see below), whose sum is σ = 327550392. Its totient is φ = 144188928.

The previous prime is 221503981. The next prime is 221504027. The reversal of 221504013 is 310405122.

221504013 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 45198729 + 176305284 = 6723^2 + 13278^2 .

It is not a de Polignac number, because 221504013 - 2⁵ = 221503981 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221504093) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 110145 + ... + 112137.

It is an arithmetic number, because the mean of its divisors is an integer number (13647933).

Almost surely, 2^221504013 is an apocalyptic number.

It is an amenable number.

221504013 is a deficient number, since it is larger than the sum of its proper divisors (106046379).

221504013 is a wasteful number, since it uses less digits than its factorization.

221504013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2285 (or 2282 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 221504013 is about 14883.0108848983. The cubic root of 221504013 is about 605.0536236421.

Adding to 221504013 its reverse (310405122), we get a palindrome (531909135).

The spelling of 221504013 in words is "two hundred twenty-one million, five hundred four thousand, thirteen".