1081581511 has 4 divisors (see below), whose sum is σ = 1081985832. Its totient is φ = 1081177192.

The previous prime is 1081581467. The next prime is 1081581533. The reversal of 1081581511 is 1151851801.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1081581511 - 2⁹ = 1081580999 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1081581541) 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, 198121 + ... + 203506.

It is an arithmetic number, because the mean of its divisors is an integer number (270496458).

Almost surely, 2^1081581511 is an apocalyptic number.

1081581511 is a deficient number, since it is larger than the sum of its proper divisors (404321).

1081581511 is an equidigital number, since it uses as much as digits as its factorization.

1081581511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404320.

The product of its (nonzero) digits is 1600, while the sum is 31.

The square root of 1081581511 is about 32887.4065715131. The cubic root of 1081581511 is about 1026.4861285236.

The spelling of 1081581511 in words is "one billion, eighty-one million, five hundred eighty-one thousand, five hundred eleven".