1581097 has 4 divisors (see below), whose sum is σ = 1806976. Its totient is φ = 1355220.

The previous prime is 1581091. The next prime is 1581101. The reversal of 1581097 is 7901851.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 7901851 = 103 ⋅76717.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1581097 is a prime.

It is a Duffinian number.

1581097 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1581091) 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, 112929 + ... + 112942.

It is an arithmetic number, because the mean of its divisors is an integer number (451744).

2^1581097 is an apocalyptic number.

It is an amenable number.

1581097 is a deficient number, since it is larger than the sum of its proper divisors (225879).

1581097 is an equidigital number, since it uses as much as digits as its factorization.

1581097 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225878.

The product of its (nonzero) digits is 2520, while the sum is 31.

The square root of 1581097 is about 1257.4167964522. The cubic root of 1581097 is about 116.4982777104.

The spelling of 1581097 in words is "one million, five hundred eighty-one thousand, ninety-seven".