1581009120 has 72 divisors (see below), whose sum is σ = 5395198536. Its totient is φ = 421602048.

The previous prime is 1581009097. The next prime is 1581009161. The reversal of 1581009120 is 219001851.

It is a tau number, because it is divible by the number of its divisors (72).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 547522 + ... + 550401.

It is an arithmetic number, because the mean of its divisors is an integer number (74933313).

Almost surely, 2^1581009120 is an apocalyptic number.

1581009120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1581009120 is an abundant number, since it is smaller than the sum of its proper divisors (3814189416).

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

1581009120 is a wasteful number, since it uses less digits than its factorization.

1581009120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1097944 (or 1097933 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 27.

The square root of 1581009120 is about 39761.9053869404. The cubic root of 1581009120 is about 1164.9611928105.

The spelling of 1581009120 in words is "one billion, five hundred eighty-one million, nine thousand, one hundred twenty".