666521467 has 2 divisors, whose sum is σ = 666521468. Its totient is φ = 666521466.

The previous prime is 666521437. The next prime is 666521473. The reversal of 666521467 is 764125666.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 666521467 - 2²³ = 658132859 is a prime.

It is not a weakly prime, because it can be changed into another prime (666521437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333260733 + 333260734.

It is an arithmetic number, because the mean of its divisors is an integer number (333260734).

Almost surely, 2^666521467 is an apocalyptic number.

666521467 is a deficient number, since it is larger than the sum of its proper divisors (1).

666521467 is an equidigital number, since it uses as much as digits as its factorization.

666521467 is an evil number, because the sum of its binary digits is even.

The product of its digits is 362880, while the sum is 43.

The square root of 666521467 is about 25817.0770421440. The cubic root of 666521467 is about 873.5170383352.

The spelling of 666521467 in words is "six hundred sixty-six million, five hundred twenty-one thousand, four hundred sixty-seven".