221257095781 has 2 divisors, whose sum is σ = 221257095782. Its totient is φ = 221257095780.

The previous prime is 221257095671. The next prime is 221257095797. The reversal of 221257095781 is 187590752122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 213897000100 + 7360095681 = 462490^2 + 85791^2 .

It is a cyclic number.

It is not a de Polignac number, because 221257095781 - 2²⁵ = 221223541349 is a prime.

It is a super-2 number, since 2×221257095781² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221257095481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110628547890 + 110628547891.

It is an arithmetic number, because the mean of its divisors is an integer number (110628547891).

Almost surely, 2^221257095781 is an apocalyptic number.

It is an amenable number.

221257095781 is a deficient number, since it is larger than the sum of its proper divisors (1).

221257095781 is an equidigital number, since it uses as much as digits as its factorization.

221257095781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 705600, while the sum is 49.

The spelling of 221257095781 in words is "two hundred twenty-one billion, two hundred fifty-seven million, ninety-five thousand, seven hundred eighty-one".