661363489 has 2 divisors, whose sum is σ = 661363490. Its totient is φ = 661363488.

The previous prime is 661363447. The next prime is 661363519. The reversal of 661363489 is 984363166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 632019600 + 29343889 = 25140^2 + 5417^2 .

It is a cyclic number.

It is not a de Polignac number, because 661363489 - 2¹⁵ = 661330721 is a prime.

It is not a weakly prime, because it can be changed into another prime (661063489) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330681744 + 330681745.

It is an arithmetic number, because the mean of its divisors is an integer number (330681745).

Almost surely, 2^661363489 is an apocalyptic number.

It is an amenable number.

661363489 is a deficient number, since it is larger than the sum of its proper divisors (1).

661363489 is an equidigital number, since it uses as much as digits as its factorization.

661363489 is an evil number, because the sum of its binary digits is even.

The product of its digits is 559872, while the sum is 46.

The square root of 661363489 is about 25716.9883345620. The cubic root of 661363489 is about 871.2579191651.

The spelling of 661363489 in words is "six hundred sixty-one million, three hundred sixty-three thousand, four hundred eighty-nine".