1660707989 has 4 divisors (see below), whose sum is σ = 1692042156. Its totient is φ = 1629373824.

The previous prime is 1660707943. The next prime is 1660708001. The reversal of 1660707989 is 9897070661.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9897070661 = 27143 ⋅364627.

It can be written as a sum of positive squares in 2 ways, for example, as 622901764 + 1037806225 = 24958^2 + 32215^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1660707989 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (53), and also a Moran number because the ratio is a prime number: 31334113 = 1660707989 / (1 + 6 + 6 + 0 + 7 + 0 + 7 + 9 + 8 + 9).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1660707989.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1660707929) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15667004 + ... + 15667109.

It is an arithmetic number, because the mean of its divisors is an integer number (423010539).

Almost surely, 2^1660707989 is an apocalyptic number.

It is an amenable number.

1660707989 is a deficient number, since it is larger than the sum of its proper divisors (31334167).

1660707989 is an equidigital number, since it uses as much as digits as its factorization.

1660707989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31334166.

The product of its (nonzero) digits is 1143072, while the sum is 53.

The square root of 1660707989 is about 40751.7851020050. The cubic root of 1660707989 is about 1184.2164555580.

The spelling of 1660707989 in words is "one billion, six hundred sixty million, seven hundred seven thousand, nine hundred eighty-nine".