1585399680 has 384 divisors, whose sum is σ = 5786557920. Its totient is φ = 399458304.

The previous prime is 1585399661. The next prime is 1585399681. The reversal of 1585399680 is 869935851.

It is a happy number.

1585399680 is a `hidden beast` number, since 15 + 8 + 539 + 96 + 8 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1585399681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 9164074 + ... + 9164246.

Almost surely, 2^1585399680 is an apocalyptic number.

1585399680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1585399680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2893278960).

1585399680 is an abundant number, since it is smaller than the sum of its proper divisors (4201158240).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1585399680 is a wasteful number, since it uses less digits than its factorization.

1585399680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 278 (or 263 counting only the distinct ones).

The product of its (nonzero) digits is 2332800, while the sum is 54.

The square root of 1585399680 is about 39817.0777430991. The cubic root of 1585399680 is about 1166.0385858304.

The spelling of 1585399680 in words is "one billion, five hundred eighty-five million, three hundred ninety-nine thousand, six hundred eighty".