221212430 has 16 divisors (see below), whose sum is σ = 402981264. Its totient is φ = 87418560.

The previous prime is 221212423. The next prime is 221212441. The reversal of 221212430 is 34212122.

It is a junction number, because it is equal to n+sod(n) for n = 221212399 and 221212408.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 132431 + ... + 134090.

It is an arithmetic number, because the mean of its divisors is an integer number (25186329).

Almost surely, 2^221212430 is an apocalyptic number.

221212430 is a deficient number, since it is larger than the sum of its proper divisors (181768834).

221212430 is a wasteful number, since it uses less digits than its factorization.

221212430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266611.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 221212430 is about 14873.2118252918. The cubic root of 221212430 is about 604.7880139762.

Adding to 221212430 its reverse (34212122), we get a palindrome (255424552).

The spelling of 221212430 in words is "two hundred twenty-one million, two hundred twelve thousand, four hundred thirty".