1581120 has 140 divisors (see below), whose sum is σ = 5716524. Its totient is φ = 414720.

The previous prime is 1581113. The next prime is 1581131. The reversal of 1581120 is 211851.

1581120 is nontrivially palindromic in base 14.

It can be written as a sum of positive squares in 2 ways, for example, as 254016 + 1327104 = 504^2 + 1152^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nialpdrome in base 12.

It is a junction number, because it is equal to n+sod(n) for n = 1581093 and 1581102.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 25890 + ... + 25950.

2^1581120 is an apocalyptic number.

1581120 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 1581120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2858262).

1581120 is an abundant number, since it is smaller than the sum of its proper divisors (4135404).

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

1581120 is an equidigital number, since it uses as much as digits as its factorization.

1581120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90 (or 71 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 18.

The square root of 1581120 is about 1257.4259421533. The cubic root of 1581120 is about 116.4988426024.

Adding to 1581120 its reverse (211851), we get a palindrome (1792971).

The spelling of 1581120 in words is "one million, five hundred eighty-one thousand, one hundred twenty".