11155166021 has 2 divisors, whose sum is σ = 11155166022. Its totient is φ = 11155166020.

The previous prime is 11155165993. The next prime is 11155166119. The reversal of 11155166021 is 12066155111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9373144225 + 1782021796 = 96815^2 + 42214^2 .

It is a cyclic number.

It is not a de Polignac number, because 11155166021 - 2²² = 11150971717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11155166621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5577583010 + 5577583011.

It is an arithmetic number, because the mean of its divisors is an integer number (5577583011).

Almost surely, 2^11155166021 is an apocalyptic number.

It is an amenable number.

11155166021 is a deficient number, since it is larger than the sum of its proper divisors (1).

11155166021 is an equidigital number, since it uses as much as digits as its factorization.

11155166021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1800, while the sum is 29.

The spelling of 11155166021 in words is "eleven billion, one hundred fifty-five million, one hundred sixty-six thousand, twenty-one".