11491513571 has 4 divisors (see below), whose sum is σ = 11493113952. Its totient is φ = 11489913192.

The previous prime is 11491513559. The next prime is 11491513637. The reversal of 11491513571 is 17531519411.

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 11491513571 - 2¹⁸ = 11491251427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11491513531) 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, 789371 + ... + 803796.

It is an arithmetic number, because the mean of its divisors is an integer number (2873278488).

Almost surely, 2^11491513571 is an apocalyptic number.

11491513571 is a deficient number, since it is larger than the sum of its proper divisors (1600381).

11491513571 is an equidigital number, since it uses as much as digits as its factorization.

11491513571 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1600380.

The product of its digits is 18900, while the sum is 38.

The spelling of 11491513571 in words is "eleven billion, four hundred ninety-one million, five hundred thirteen thousand, five hundred seventy-one".