11321009981 has 2 divisors, whose sum is σ = 11321009982. Its totient is φ = 11321009980.

The previous prime is 11321009969. The next prime is 11321010011. The reversal of 11321009981 is 18990012311.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8433667225 + 2887342756 = 91835^2 + 53734^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11321009981 is a prime.

It is a super-2 number, since 2×11321009981² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11321009911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5660504990 + 5660504991.

It is an arithmetic number, because the mean of its divisors is an integer number (5660504991).

Almost surely, 2^11321009981 is an apocalyptic number.

It is an amenable number.

11321009981 is a deficient number, since it is larger than the sum of its proper divisors (1).

11321009981 is an equidigital number, since it uses as much as digits as its factorization.

11321009981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 35.

The spelling of 11321009981 in words is "eleven billion, three hundred twenty-one million, nine thousand, nine hundred eighty-one".