221761457 has 2 divisors, whose sum is σ = 221761458. Its totient is φ = 221761456.

The previous prime is 221761451. The next prime is 221761499. The reversal of 221761457 is 754167122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 202322176 + 19439281 = 14224^2 + 4409^2 .

It is a cyclic number.

It is not a de Polignac number, because 221761457 - 2¹⁰ = 221760433 is a prime.

It is not a weakly prime, because it can be changed into another prime (221761451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110880728 + 110880729.

It is an arithmetic number, because the mean of its divisors is an integer number (110880729).

Almost surely, 2^221761457 is an apocalyptic number.

It is an amenable number.

221761457 is a deficient number, since it is larger than the sum of its proper divisors (1).

221761457 is an equidigital number, since it uses as much as digits as its factorization.

221761457 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23520, while the sum is 35.

The square root of 221761457 is about 14891.6572952778. The cubic root of 221761457 is about 605.2879416195.

The spelling of 221761457 in words is "two hundred twenty-one million, seven hundred sixty-one thousand, four hundred fifty-seven".