1166516621 has 2 divisors, whose sum is σ = 1166516622. Its totient is φ = 1166516620.

The previous prime is 1166516579. The next prime is 1166516623. The reversal of 1166516621 is 1266156611.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 768952900 + 397563721 = 27730^2 + 19939^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1166516621 is a prime.

It is a super-2 number, since 2×1166516621² = 2721522054138515282, which contains 22 as substring.

Together with 1166516623, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1166516623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 583258310 + 583258311.

It is an arithmetic number, because the mean of its divisors is an integer number (583258311).

Almost surely, 2^1166516621 is an apocalyptic number.

It is an amenable number.

1166516621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1166516621 is an equidigital number, since it uses as much as digits as its factorization.

1166516621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12960, while the sum is 35.

The square root of 1166516621 is about 34154.3060389170. The cubic root of 1166516621 is about 1052.6814670847.

The spelling of 1166516621 in words is "one billion, one hundred sixty-six million, five hundred sixteen thousand, six hundred twenty-one".