221621242513 has 32 divisors (see below), whose sum is σ = 247140052992. Its totient is φ = 197045956800.

The previous prime is 221621242501. The next prime is 221621242559. The reversal of 221621242513 is 315242126122.

It is a happy number.

It is not a de Polignac number, because 221621242513 - 2⁹ = 221621242001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221621240513) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 69190170 + ... + 69193372.

It is an arithmetic number, because the mean of its divisors is an integer number (7723126656).

Almost surely, 2^221621242513 is an apocalyptic number.

It is an amenable number.

221621242513 is a deficient number, since it is larger than the sum of its proper divisors (25518810479).

221621242513 is a wasteful number, since it uses less digits than its factorization.

221621242513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3925.

The product of its digits is 11520, while the sum is 31.

Adding to 221621242513 its reverse (315242126122), we get a palindrome (536863368635).

The spelling of 221621242513 in words is "two hundred twenty-one billion, six hundred twenty-one million, two hundred forty-two thousand, five hundred thirteen".