1581609872 has 20 divisors (see below), whose sum is σ = 3065434380. Its totient is φ = 790530048.

The previous prime is 1581609871. The next prime is 1581609877. The reversal of 1581609872 is 2789061851.

It can be written as a sum of positive squares in 2 ways, for example, as 1062499216 + 519110656 = 32596^2 + 22784^2 .

It is not an unprimeable number, because it can be changed into a prime (1581609871) 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, 35108 + ... + 66300.

It is an arithmetic number, because the mean of its divisors is an integer number (153271719).

Almost surely, 2^1581609872 is an apocalyptic number.

It is an amenable number.

1581609872 is a deficient number, since it is larger than the sum of its proper divisors (1483824508).

1581609872 is a wasteful number, since it uses less digits than its factorization.

1581609872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34370 (or 34364 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 47.

The square root of 1581609872 is about 39769.4590357978. The cubic root of 1581609872 is about 1165.1087281479.

The spelling of 1581609872 in words is "one billion, five hundred eighty-one million, six hundred nine thousand, eight hundred seventy-two".