11531531 has 16 divisors (see below), whose sum is σ = 13379040. Its totient is φ = 9838080.

The previous prime is 11531521. The next prime is 11531539. The reversal of 11531531 is 13513511.

It is a cyclic number.

It is not a de Polignac number, because 11531531 - 2⁶ = 11531467 is a prime.

It is a super-2 number, since 2×11531531² = 265952414407922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11531539) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11315 + ... + 12291.

It is an arithmetic number, because the mean of its divisors is an integer number (836190).

Almost surely, 2^11531531 is an apocalyptic number.

11531531 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

11531531 is a deficient number, since it is larger than the sum of its proper divisors (1847509).

11531531 is a wasteful number, since it uses less digits than its factorization.

11531531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1054.

The product of its digits is 225, while the sum is 20.

The square root of 11531531 is about 3395.8108015612. The cubic root of 11531531 is about 225.9239765702.

The spelling of 11531531 in words is "eleven million, five hundred thirty-one thousand, five hundred thirty-one".