221221047577 has 2 divisors, whose sum is σ = 221221047578. Its totient is φ = 221221047576.

The previous prime is 221221047539. The next prime is 221221047653. The reversal of 221221047577 is 775740122122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 159747299856 + 61473747721 = 399684^2 + 247939^2 .

It is a cyclic number.

It is not a de Polignac number, because 221221047577 - 2²³ = 221212658969 is a prime.

It is not a weakly prime, because it can be changed into another prime (221221047517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110610523788 + 110610523789.

It is an arithmetic number, because the mean of its divisors is an integer number (110610523789).

Almost surely, 2^221221047577 is an apocalyptic number.

It is an amenable number.

221221047577 is a deficient number, since it is larger than the sum of its proper divisors (1).

221221047577 is an equidigital number, since it uses as much as digits as its factorization.

221221047577 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 109760, while the sum is 40.

Adding to 221221047577 its reverse (775740122122), we get a palindrome (996961169699).

The spelling of 221221047577 in words is "two hundred twenty-one billion, two hundred twenty-one million, forty-seven thousand, five hundred seventy-seven".