221312040251 has 2 divisors, whose sum is σ = 221312040252. Its totient is φ = 221312040250.

The previous prime is 221312040247. The next prime is 221312040277. The reversal of 221312040251 is 152040213122.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221312040251 - 2² = 221312040247 is a prime.

It is not a weakly prime, because it can be changed into another prime (221312049251) 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 as a sum of consecutive naturals, namely, 110656020125 + 110656020126.

It is an arithmetic number, because the mean of its divisors is an integer number (110656020126).

Almost surely, 2^221312040251 is an apocalyptic number.

221312040251 is a deficient number, since it is larger than the sum of its proper divisors (1).

221312040251 is an equidigital number, since it uses as much as digits as its factorization.

221312040251 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 960, while the sum is 23.

Adding to 221312040251 its reverse (152040213122), we get a palindrome (373352253373).

The spelling of 221312040251 in words is "two hundred twenty-one billion, three hundred twelve million, forty thousand, two hundred fifty-one".