662660989 has 2 divisors, whose sum is σ = 662660990. Its totient is φ = 662660988.

The previous prime is 662660987. The next prime is 662661017. The reversal of 662660989 is 989066266.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 502208100 + 160452889 = 22410^2 + 12667^2 .

It is a cyclic number.

It is not a de Polignac number, because 662660989 - 2¹ = 662660987 is a prime.

Together with 662660987, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (662660987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 331330494 + 331330495.

It is an arithmetic number, because the mean of its divisors is an integer number (331330495).

Almost surely, 2^662660989 is an apocalyptic number.

It is an amenable number.

662660989 is a deficient number, since it is larger than the sum of its proper divisors (1).

662660989 is an equidigital number, since it uses as much as digits as its factorization.

662660989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1679616, while the sum is 52.

The square root of 662660989 is about 25742.2024892976. The cubic root of 662660989 is about 871.8273078643.

The spelling of 662660989 in words is "six hundred sixty-two million, six hundred sixty thousand, nine hundred eighty-nine".