221264613 has 18 divisors (see below), whose sum is σ = 324235782. Its totient is φ = 145402320.

The previous prime is 221264611. The next prime is 221264621. The reversal of 221264613 is 316462122.

221264613 is a `hidden beast` number, since 2 + 2 + 1 + 2 + 646 + 13 = 666.

221264613 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 only one way, i.e., 168818049 + 52446564 = 12993^2 + 7242^2 .

It is not a de Polignac number, because 221264613 - 2¹ = 221264611 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221264611) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 42931 + ... + 47807.

It is an arithmetic number, because the mean of its divisors is an integer number (18013099).

Almost surely, 2^221264613 is an apocalyptic number.

It is an amenable number.

221264613 is a deficient number, since it is larger than the sum of its proper divisors (102971169).

221264613 is an equidigital number, since it uses as much as digits as its factorization.

221264613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5025 (or 4951 counting only the distinct ones).

The product of its digits is 3456, while the sum is 27.

The square root of 221264613 is about 14874.9659831544. The cubic root of 221264613 is about 604.8355658123.

The spelling of 221264613 in words is "two hundred twenty-one million, two hundred sixty-four thousand, six hundred thirteen".