11663531 has 4 divisors (see below), whose sum is σ = 12723864. Its totient is φ = 10603200.

The previous prime is 11663527. The next prime is 11663543. The reversal of 11663531 is 13536611.

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 11663531 - 2² = 11663527 is a prime.

It is a super-2 number, since 2×11663531² = 272075910775922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 11663531.

It is not an unprimeable number, because it can be changed into a prime (11663501) 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, 530150 + ... + 530171.

It is an arithmetic number, because the mean of its divisors is an integer number (3180966).

Almost surely, 2^11663531 is an apocalyptic number.

11663531 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

11663531 is a deficient number, since it is larger than the sum of its proper divisors (1060333).

11663531 is a wasteful number, since it uses less digits than its factorization.

11663531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1060332.

The product of its digits is 1620, while the sum is 26.

The square root of 11663531 is about 3415.1912098739. The cubic root of 11663531 is about 226.7827493160.

Subtracting 11663531 from its reverse (13536611), we obtain a triangular number (1873080 = T₁₉₃₅).

The spelling of 11663531 in words is "eleven million, six hundred sixty-three thousand, five hundred thirty-one".