661122247 has 2 divisors, whose sum is σ = 661122248. Its totient is φ = 661122246.

The previous prime is 661122181. The next prime is 661122311. The reversal of 661122247 is 742221166.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 661122247 - 2²³ = 652733639 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (661129247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330561123 + 330561124.

It is an arithmetic number, because the mean of its divisors is an integer number (330561124).

Almost surely, 2^661122247 is an apocalyptic number.

661122247 is a deficient number, since it is larger than the sum of its proper divisors (1).

661122247 is an equidigital number, since it uses as much as digits as its factorization.

661122247 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8064, while the sum is 31.

The square root of 661122247 is about 25712.2975830632. The cubic root of 661122247 is about 871.1519715950.

The spelling of 661122247 in words is "six hundred sixty-one million, one hundred twenty-two thousand, two hundred forty-seven".