221221242031 has 4 divisors (see below), whose sum is σ = 221245331032. Its totient is φ = 221197153032.

The previous prime is 221221242023. The next prime is 221221242049. The reversal of 221221242031 is 130242122122.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 221221242031 - 2³ = 221221242023 is a prime.

It is a super-2 number, since 2×221221242031² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221221241993 and 221221242011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221221249031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12030720 + ... + 12049093.

It is an arithmetic number, because the mean of its divisors is an integer number (55311332758).

Almost surely, 2^221221242031 is an apocalyptic number.

221221242031 is a deficient number, since it is larger than the sum of its proper divisors (24089001).

221221242031 is an equidigital number, since it uses as much as digits as its factorization.

221221242031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24089000.

The product of its (nonzero) digits is 768, while the sum is 22.

Adding to 221221242031 its reverse (130242122122), we get a palindrome (351463364153).

The spelling of 221221242031 in words is "two hundred twenty-one billion, two hundred twenty-one million, two hundred forty-two thousand, thirty-one".