221520013 has 32 divisors (see below), whose sum is σ = 277385472. Its totient is φ = 173798400.

The previous prime is 221520011. The next prime is 221520037. The reversal of 221520013 is 310025122.

It is a cyclic number.

It is not a de Polignac number, because 221520013 - 2¹ = 221520011 is a prime.

It is a super-2 number, since 2×221520013² = 98142232319040338, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221520011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 712128 + ... + 712438.

It is an arithmetic number, because the mean of its divisors is an integer number (8668296).

Almost surely, 2^221520013 is an apocalyptic number.

It is an amenable number.

221520013 is a deficient number, since it is larger than the sum of its proper divisors (55865459).

221520013 is a wasteful number, since it uses less digits than its factorization.

221520013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 645.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 221520013 is about 14883.5484008351. The cubic root of 221520013 is about 605.0681916625.

Adding to 221520013 its reverse (310025122), we get a palindrome (531545135).

The spelling of 221520013 in words is "two hundred twenty-one million, five hundred twenty thousand, thirteen".