11527981 has 4 divisors (see below), whose sum is σ = 11605500. Its totient is φ = 11450464.

The previous prime is 11527973. The next prime is 11527987. The reversal of 11527981 is 18972511.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18972511 = 257 ⋅73823.

It can be written as a sum of positive squares in 2 ways, for example, as 538756 + 10989225 = 734^2 + 3315^2 .

It is a cyclic number.

It is not a de Polignac number, because 11527981 - 2³ = 11527973 is a prime.

It is a super-2 number, since 2×11527981² = 265788691872722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11527987) 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, 38536 + ... + 38833.

It is an arithmetic number, because the mean of its divisors is an integer number (2901375).

Almost surely, 2^11527981 is an apocalyptic number.

It is an amenable number.

11527981 is a deficient number, since it is larger than the sum of its proper divisors (77519).

11527981 is an equidigital number, since it uses as much as digits as its factorization.

11527981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77518.

The product of its digits is 5040, while the sum is 34.

The square root of 11527981 is about 3395.2880584716. The cubic root of 11527981 is about 225.9007905066.

The spelling of 11527981 in words is "eleven million, five hundred twenty-seven thousand, nine hundred eighty-one".