2166520481 has 2 divisors, whose sum is σ = 2166520482. Its totient is φ = 2166520480.

The previous prime is 2166520463. The next prime is 2166520493. The reversal of 2166520481 is 1840256612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1483482256 + 683038225 = 38516^2 + 26135^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2166520481 is a prime.

It is a super-3 number, since 3×2166520481³ (a number of 29 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (2166520441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1083260240 + 1083260241.

It is an arithmetic number, because the mean of its divisors is an integer number (1083260241).

Almost surely, 2^2166520481 is an apocalyptic number.

It is an amenable number.

2166520481 is a deficient number, since it is larger than the sum of its proper divisors (1).

2166520481 is an equidigital number, since it uses as much as digits as its factorization.

2166520481 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23040, while the sum is 35.

The square root of 2166520481 is about 46545.8965001213. The cubic root of 2166520481 is about 1293.9602435017.

The spelling of 2166520481 in words is "two billion, one hundred sixty-six million, five hundred twenty thousand, four hundred eighty-one".