1659011989 has 4 divisors (see below), whose sum is σ = 1690314156. Its totient is φ = 1627709824.

The previous prime is 1659011983. The next prime is 1659011993. The reversal of 1659011989 is 9891109561.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1099452964 + 559559025 = 33158^2 + 23655^2 .

It is a cyclic number.

It is not a de Polignac number, because 1659011989 - 2⁹ = 1659011477 is a prime.

It is a super-2 number, since 2×1659011989² = 5504641559291472242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1659011983) 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, 15651004 + ... + 15651109.

It is an arithmetic number, because the mean of its divisors is an integer number (422578539).

Almost surely, 2^1659011989 is an apocalyptic number.

It is an amenable number.

1659011989 is a deficient number, since it is larger than the sum of its proper divisors (31302167).

1659011989 is an equidigital number, since it uses as much as digits as its factorization.

1659011989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31302166.

The product of its (nonzero) digits is 174960, while the sum is 49.

The square root of 1659011989 is about 40730.9708821187. The cubic root of 1659011989 is about 1183.8131907628.

The spelling of 1659011989 in words is "one billion, six hundred fifty-nine million, eleven thousand, nine hundred eighty-nine".