667808969 has 2 divisors, whose sum is σ = 667808970. Its totient is φ = 667808968.

The previous prime is 667808951. The next prime is 667809007. The reversal of 667808969 is 969808766.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 423824569 + 243984400 = 20587^2 + 15620^2 .

It is a cyclic number.

It is not a de Polignac number, because 667808969 - 2²⁴ = 651031753 is a prime.

It is a super-2 number, since 2×667808969² = 891937638153685922, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (667808269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333904484 + 333904485.

It is an arithmetic number, because the mean of its divisors is an integer number (333904485).

Almost surely, 2^667808969 is an apocalyptic number.

It is an amenable number.

667808969 is a deficient number, since it is larger than the sum of its proper divisors (1).

667808969 is an equidigital number, since it uses as much as digits as its factorization.

667808969 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7838208, while the sum is 59.

The square root of 667808969 is about 25842.0000967417. Note that the first 4 decimals coincide. The cubic root of 667808969 is about 874.0791265350.

The spelling of 667808969 in words is "six hundred sixty-seven million, eight hundred eight thousand, nine hundred sixty-nine".