1581481 has 8 divisors (see below), whose sum is σ = 1742400. Its totient is φ = 1423440.

The previous prime is 1581479. The next prime is 1581487. The reversal of 1581481 is 1841851.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1581481 - 2¹ = 1581479 is a prime.

It is a super-2 number, since 2×1581481² = 5002164306722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1581487) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 540 + ... + 1858.

It is an arithmetic number, because the mean of its divisors is an integer number (217800).

2^1581481 is an apocalyptic number.

1581481 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1581481 is a deficient number, since it is larger than the sum of its proper divisors (160919).

1581481 is a wasteful number, since it uses less digits than its factorization.

1581481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1439.

The product of its digits is 1280, while the sum is 28.

The square root of 1581481 is about 1257.5694811819. The cubic root of 1581481 is about 116.5077082339.

The spelling of 1581481 in words is "one million, five hundred eighty-one thousand, four hundred eighty-one".