667612705517 has 4 divisors (see below), whose sum is σ = 667614349500. Its totient is φ = 667611061536.

The previous prime is 667612705481. The next prime is 667612705519. The reversal of 667612705517 is 715507216766.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 630720284041 + 36892421476 = 794179^2 + 192074^2 .

It is a cyclic number.

It is not a de Polignac number, because 667612705517 - 2³² = 663317738221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667612705519) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 276359 + ... + 1188107.

It is an arithmetic number, because the mean of its divisors is an integer number (166903587375).

Almost surely, 2^667612705517 is an apocalyptic number.

It is an amenable number.

667612705517 is a deficient number, since it is larger than the sum of its proper divisors (1643983).

667612705517 is an equidigital number, since it uses as much as digits as its factorization.

667612705517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1643982.

The product of its (nonzero) digits is 3704400, while the sum is 53.

The spelling of 667612705517 in words is "six hundred sixty-seven billion, six hundred twelve million, seven hundred five thousand, five hundred seventeen".