221345613 has 6 divisors (see below), whose sum is σ = 319721454. Its totient is φ = 147563736.

The previous prime is 221345599. The next prime is 221345647. The reversal of 221345613 is 316543122.

221345613 is a `hidden beast` number, since 2 + 2 + 1 + 3 + 45 + 613 = 666.

It can be written as a sum of positive squares in only one way, i.e., 133679844 + 87665769 = 11562^2 + 9363^2 .

It is not a de Polignac number, because 221345613 - 2¹⁸ = 221083469 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221345693) 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, 12296970 + ... + 12296987.

It is an arithmetic number, because the mean of its divisors is an integer number (53286909).

Almost surely, 2^221345613 is an apocalyptic number.

It is an amenable number.

221345613 is a deficient number, since it is larger than the sum of its proper divisors (98375841).

221345613 is a wasteful number, since it uses less digits than its factorization.

221345613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24593963 (or 24593960 counting only the distinct ones).

The product of its digits is 4320, while the sum is 27.

The square root of 221345613 is about 14877.6884293226. The cubic root of 221345613 is about 604.9093623752.

Adding to 221345613 its reverse (316543122), we get a palindrome (537888735).

The spelling of 221345613 in words is "two hundred twenty-one million, three hundred forty-five thousand, six hundred thirteen".