667661419 has 2 divisors, whose sum is σ = 667661420. Its totient is φ = 667661418.

The previous prime is 667661399. The next prime is 667661429. The reversal of 667661419 is 914166766.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 667661419 - 2¹³ = 667653227 is a prime.

It is a super-2 number, since 2×667661419² = 891543540842187122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (667661429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333830709 + 333830710.

It is an arithmetic number, because the mean of its divisors is an integer number (333830710).

Almost surely, 2^667661419 is an apocalyptic number.

667661419 is a deficient number, since it is larger than the sum of its proper divisors (1).

667661419 is an equidigital number, since it uses as much as digits as its factorization.

667661419 is an evil number, because the sum of its binary digits is even.

The product of its digits is 326592, while the sum is 46.

The square root of 667661419 is about 25839.1450903469. The cubic root of 667661419 is about 874.0147469091.

The spelling of 667661419 in words is "six hundred sixty-seven million, six hundred sixty-one thousand, four hundred nineteen".