221240431 has 8 divisors (see below), whose sum is σ = 235660320. Its totient is φ = 206976768.

The previous prime is 221240423. The next prime is 221240441. The reversal of 221240431 is 134042122.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 221240431 - 2³ = 221240423 is a prime.

It is a super-2 number, since 2×221240431² = 97894656618131522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221240399 and 221240408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221240441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36126 + ... + 41803.

It is an arithmetic number, because the mean of its divisors is an integer number (29457540).

Almost surely, 2^221240431 is an apocalyptic number.

221240431 is a deficient number, since it is larger than the sum of its proper divisors (14419889).

221240431 is a wasteful number, since it uses less digits than its factorization.

221240431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78113.

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 221240431 is about 14874.1531187493. The cubic root of 221240431 is about 604.8135308586.

Adding to 221240431 its reverse (134042122), we get a palindrome (355282553).

The spelling of 221240431 in words is "two hundred twenty-one million, two hundred forty thousand, four hundred thirty-one".