1591278659 has 4 divisors (see below), whose sum is σ = 1684883304. Its totient is φ = 1497674016.

The previous prime is 1591278643. The next prime is 1591278677. The reversal of 1591278659 is 9568721951.

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: 9568721951 = 89363 ⋅107077.

It is a cyclic number.

It is not a de Polignac number, because 1591278659 - 2⁴ = 1591278643 is a prime.

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 1591278659.

It is not an unprimeable number, because it can be changed into a prime (1591278959) 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, 46802297 + ... + 46802330.

It is an arithmetic number, because the mean of its divisors is an integer number (421220826).

Almost surely, 2^1591278659 is an apocalyptic number.

1591278659 is a deficient number, since it is larger than the sum of its proper divisors (93604645).

1591278659 is an equidigital number, since it uses as much as digits as its factorization.

1591278659 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93604644.

The product of its digits is 1360800, while the sum is 53.

The square root of 1591278659 is about 39890.8342730507. The cubic root of 1591278659 is about 1167.4781093521.

The spelling of 1591278659 in words is "one billion, five hundred ninety-one million, two hundred seventy-eight thousand, six hundred fifty-nine".