667556377 has 2 divisors, whose sum is σ = 667556378. Its totient is φ = 667556376.

The previous prime is 667556371. The next prime is 667556389. The reversal of 667556377 is 773655766.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 448634761 + 218921616 = 21181^2 + 14796^2 .

It is a cyclic number.

It is not a de Polignac number, because 667556377 - 2²⁷ = 533338649 is a prime.

It is a super-2 number, since 2×667556377² = 891263032946732258, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (667556371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333778188 + 333778189.

It is an arithmetic number, because the mean of its divisors is an integer number (333778189).

Almost surely, 2^667556377 is an apocalyptic number.

It is an amenable number.

667556377 is a deficient number, since it is larger than the sum of its proper divisors (1).

667556377 is an equidigital number, since it uses as much as digits as its factorization.

667556377 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5556600, while the sum is 52.

The square root of 667556377 is about 25837.1123967056. The cubic root of 667556377 is about 873.9689087694.

The spelling of 667556377 in words is "six hundred sixty-seven million, five hundred fifty-six thousand, three hundred seventy-seven".