221211442431 has 24 divisors (see below), whose sum is σ = 367028142624. Its totient is φ = 125764873920.

The previous prime is 221211442409. The next prime is 221211442433. The reversal of 221211442431 is 134244112122.

221211442431 is a `hidden beast` number, since 2 + 2 + 1 + 211 + 442 + 4 + 3 + 1 = 666.

It is not a de Polignac number, because 221211442431 - 2⁵ = 221211442399 is a prime.

It is a super-2 number, since 2×221211442431² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 221211442395 and 221211442404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221211442433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8899500 + ... + 8924321.

It is an arithmetic number, because the mean of its divisors is an integer number (15292839276).

Almost surely, 2^221211442431 is an apocalyptic number.

221211442431 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

221211442431 is a deficient number, since it is larger than the sum of its proper divisors (145816700193).

221211442431 is a wasteful number, since it uses less digits than its factorization.

221211442431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17824031 (or 17824028 counting only the distinct ones).

The product of its digits is 3072, while the sum is 27.

Adding to 221211442431 its reverse (134244112122), we get a palindrome (355455554553).

The spelling of 221211442431 in words is "two hundred twenty-one billion, two hundred eleven million, four hundred forty-two thousand, four hundred thirty-one".