1662660997 has 2 divisors, whose sum is σ = 1662660998. Its totient is φ = 1662660996.

The previous prime is 1662660959. The next prime is 1662661009. The reversal of 1662660997 is 7990662661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1570616161 + 92044836 = 39631^2 + 9594^2 .

It is an emirp because it is prime and its reverse (7990662661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1662660997 - 2¹⁹ = 1662136709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1662660947) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 831330498 + 831330499.

It is an arithmetic number, because the mean of its divisors is an integer number (831330499).

Almost surely, 2^1662660997 is an apocalyptic number.

It is an amenable number.

1662660997 is a deficient number, since it is larger than the sum of its proper divisors (1).

1662660997 is an equidigital number, since it uses as much as digits as its factorization.

1662660997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1469664, while the sum is 52.

The square root of 1662660997 is about 40775.7402998401. The cubic root of 1662660997 is about 1184.6804902147.

The spelling of 1662660997 in words is "one billion, six hundred sixty-two million, six hundred sixty thousand, nine hundred ninety-seven".