11531999999 has 8 divisors (see below), whose sum is σ = 12488459760. Its totient is φ = 10585452096.

The previous prime is 11531999981. The next prime is 11532000037. The reversal of 11531999999 is 99999913511.

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 11531999999 - 2¹² = 11531995903 is a prime.

It is a Duffinian number.

11531999999 is a modest number, since divided by 999999 gives 11531 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11531999939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2475542 + ... + 2480195.

It is an arithmetic number, because the mean of its divisors is an integer number (1561057470).

Almost surely, 2^11531999999 is an apocalyptic number.

11531999999 is a deficient number, since it is larger than the sum of its proper divisors (956459761).

11531999999 is a wasteful number, since it uses less digits than its factorization.

11531999999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4955929.

The product of its digits is 7971615, while the sum is 65.

The spelling of 11531999999 in words is "eleven billion, five hundred thirty-one million, nine hundred ninety-nine thousand, nine hundred ninety-nine".