766161821 has 2 divisors, whose sum is σ = 766161822. Its totient is φ = 766161820.

The previous prime is 766161761. The next prime is 766161841. The reversal of 766161821 is 128161667.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 627252025 + 138909796 = 25045^2 + 11786^2 .

It is a cyclic number.

It is not a de Polignac number, because 766161821 - 2¹⁸ = 765899677 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (766161841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 383080910 + 383080911.

It is an arithmetic number, because the mean of its divisors is an integer number (383080911).

Almost surely, 2^766161821 is an apocalyptic number.

It is an amenable number.

766161821 is a deficient number, since it is larger than the sum of its proper divisors (1).

766161821 is an equidigital number, since it uses as much as digits as its factorization.

766161821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24192, while the sum is 38.

The square root of 766161821 is about 27679.6282670125. The cubic root of 766161821 is about 915.0401889442.

The spelling of 766161821 in words is "seven hundred sixty-six million, one hundred sixty-one thousand, eight hundred twenty-one".