11428981 has 4 divisors (see below), whose sum is σ = 12101292. Its totient is φ = 10756672.

The previous prime is 11428969. The next prime is 11428993. The reversal of 11428981 is 18982411.

11428981 = 2390² + 2391².

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (11428969) and next prime (11428993).

It can be written as a sum of positive squares in 2 ways, for example, as 5712100 + 5716881 = 2390^2 + 2391^2 .

It is a cyclic number.

It is not a de Polignac number, because 11428981 - 2⁷ = 11428853 is a prime.

It is a super-2 number, since 2×11428981² = 261243213396722, 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 (11428931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 336130 + ... + 336163.

It is an arithmetic number, because the mean of its divisors is an integer number (3025323).

Almost surely, 2^11428981 is an apocalyptic number.

11428981 is the 2391-st centered square number.

It is an amenable number.

11428981 is a deficient number, since it is larger than the sum of its proper divisors (672311).

11428981 is an equidigital number, since it uses as much as digits as its factorization.

11428981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 672310.

The product of its digits is 4608, while the sum is 34.

The square root of 11428981 is about 3380.6775948026. The cubic root of 11428981 is about 225.2522668505.

The spelling of 11428981 in words is "eleven million, four hundred twenty-eight thousand, nine hundred eighty-one".