221315513 has 4 divisors (see below), whose sum is σ = 222439140. Its totient is φ = 220191888.

The previous prime is 221315429. The next prime is 221315519. The reversal of 221315513 is 315513122.

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 215150224 + 6165289 = 14668^2 + 2483^2 .

It is a cyclic number.

It is not a de Polignac number, because 221315513 - 2⁸ = 221315257 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (221315519) 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, 561518 + ... + 561911.

It is an arithmetic number, because the mean of its divisors is an integer number (55609785).

Almost surely, 2^221315513 is an apocalyptic number.

It is an amenable number.

221315513 is a deficient number, since it is larger than the sum of its proper divisors (1123627).

221315513 is a wasteful number, since it uses less digits than its factorization.

221315513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1123626.

The product of its digits is 900, while the sum is 23.

The square root of 221315513 is about 14876.6768130520. The cubic root of 221315513 is about 604.8819413104.

Adding to 221315513 its reverse (315513122), we get a palindrome (536828635).

The spelling of 221315513 in words is "two hundred twenty-one million, three hundred fifteen thousand, five hundred thirteen".