1659442385 has 4 divisors (see below), whose sum is σ = 1991330868. Its totient is φ = 1327553904.

The previous prime is 1659442381. The next prime is 1659442391. The reversal of 1659442385 is 5832449561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5832449561 = 20959 ⋅278279.

It can be written as a sum of positive squares in 2 ways, for example, as 404653456 + 1254788929 = 20116^2 + 35423^2 .

It is a cyclic number.

It is not a de Polignac number, because 1659442385 - 2² = 1659442381 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1659442381) 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, 165944234 + ... + 165944243.

It is an arithmetic number, because the mean of its divisors is an integer number (497832717).

Almost surely, 2^1659442385 is an apocalyptic number.

It is an amenable number.

1659442385 is a deficient number, since it is larger than the sum of its proper divisors (331888483).

1659442385 is an equidigital number, since it uses as much as digits as its factorization.

1659442385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331888482.

The product of its digits is 1036800, while the sum is 47.

The square root of 1659442385 is about 40736.2539392124. The cubic root of 1659442385 is about 1183.9155537779.

The spelling of 1659442385 in words is "one billion, six hundred fifty-nine million, four hundred forty-two thousand, three hundred eighty-five".