2166520493 has 2 divisors, whose sum is σ = 2166520494. Its totient is φ = 2166520492.

The previous prime is 2166520481. The next prime is 2166520501. The reversal of 2166520493 is 3940256612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1285796164 + 880724329 = 35858^2 + 29677^2 .

It is a cyclic number.

It is not a de Polignac number, because 2166520493 - 2³⁰ = 1092778669 is a prime.

It is a super-2 number, since 2×2166520493² = 9387622093177926098, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2166520403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1083260246 + 1083260247.

It is an arithmetic number, because the mean of its divisors is an integer number (1083260247).

Almost surely, 2^2166520493 is an apocalyptic number.

It is an amenable number.

2166520493 is a deficient number, since it is larger than the sum of its proper divisors (1).

2166520493 is an equidigital number, since it uses as much as digits as its factorization.

2166520493 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 77760, while the sum is 38.

The square root of 2166520493 is about 46545.8966290263. The cubic root of 2166520493 is about 1293.9602458908.

The spelling of 2166520493 in words is "two billion, one hundred sixty-six million, five hundred twenty thousand, four hundred ninety-three".