667665070426621 has 4 divisors (see below), whose sum is σ = 702805337291200. Its totient is φ = 632524803562044.

The previous prime is 667665070426579. The next prime is 667665070426631. The reversal of 667665070426621 is 126624070566766.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 667665070426621 - 2¹⁹ = 667665069902333 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 (667665070426631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17570133432261 + ... + 17570133432298.

It is an arithmetic number, because the mean of its divisors is an integer number (175701334322800).

Almost surely, 2^{667665070426621} is an apocalyptic number.

It is an amenable number.

667665070426621 is a deficient number, since it is larger than the sum of its proper divisors (35140266864579).

667665070426621 is a wasteful number, since it uses less digits than its factorization.

667665070426621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35140266864578.

The product of its (nonzero) digits is 182891520, while the sum is 64.

The spelling of 667665070426621 in words is "six hundred sixty-seven trillion, six hundred sixty-five billion, seventy million, four hundred twenty-six thousand, six hundred twenty-one".