221243013 has 6 divisors (see below), whose sum is σ = 319573254. Its totient is φ = 147495336.

The previous prime is 221242999. The next prime is 221243021. The reversal of 221243013 is 310342122.

221243013 is a `hidden beast` number, since 221 + 2 + 430 + 13 = 666.

It can be written as a sum of positive squares in only one way, i.e., 185995044 + 35247969 = 13638^2 + 5937^2 .

It is not a de Polignac number, because 221243013 - 2⁶ = 221242949 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221243023) 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, 12291270 + ... + 12291287.

It is an arithmetic number, because the mean of its divisors is an integer number (53262209).

Almost surely, 2^221243013 is an apocalyptic number.

It is an amenable number.

221243013 is a deficient number, since it is larger than the sum of its proper divisors (98330241).

221243013 is a wasteful number, since it uses less digits than its factorization.

221243013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24582563 (or 24582560 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 221243013 is about 14874.2399133536. The cubic root of 221243013 is about 604.8158836873.

Adding to 221243013 its reverse (310342122), we get a palindrome (531585135).

The spelling of 221243013 in words is "two hundred twenty-one million, two hundred forty-three thousand, thirteen".