1689802561 has 4 divisors (see below), whose sum is σ = 1710161712. Its totient is φ = 1669443412.

The previous prime is 1689802553. The next prime is 1689802579. The reversal of 1689802561 is 1652089861.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1689802561 - 2³ = 1689802553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1689802501) 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, 10179451 + ... + 10179616.

It is an arithmetic number, because the mean of its divisors is an integer number (427540428).

Almost surely, 2^1689802561 is an apocalyptic number.

It is an amenable number.

1689802561 is a deficient number, since it is larger than the sum of its proper divisors (20359151).

1689802561 is an equidigital number, since it uses as much as digits as its factorization.

1689802561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20359150.

The product of its (nonzero) digits is 207360, while the sum is 46.

The square root of 1689802561 is about 41107.2081392060. The cubic root of 1689802561 is about 1191.0920373585.

The spelling of 1689802561 in words is "one billion, six hundred eighty-nine million, eight hundred two thousand, five hundred sixty-one".