661846489 has 2 divisors, whose sum is σ = 661846490. Its totient is φ = 661846488.

The previous prime is 661846441. The next prime is 661846529. The reversal of 661846489 is 984648166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 480486400 + 181360089 = 21920^2 + 13467^2 .

It is a cyclic number.

It is not a de Polignac number, because 661846489 - 2²⁹ = 124975577 is a prime.

It is not a weakly prime, because it can be changed into another prime (661846429) 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, 330923244 + 330923245.

It is an arithmetic number, because the mean of its divisors is an integer number (330923245).

Almost surely, 2^661846489 is an apocalyptic number.

It is an amenable number.

661846489 is a deficient number, since it is larger than the sum of its proper divisors (1).

661846489 is an equidigital number, since it uses as much as digits as its factorization.

661846489 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1990656, while the sum is 52.

The square root of 661846489 is about 25726.3773003507. The cubic root of 661846489 is about 871.4699635155.

The spelling of 661846489 in words is "six hundred sixty-one million, eight hundred forty-six thousand, four hundred eighty-nine".