667651620761 has 4 divisors (see below), whose sum is σ = 667801222272. Its totient is φ = 667502019252.

The previous prime is 667651620739. The next prime is 667651620827. The reversal of 667651620761 is 167026156766.

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 667651620761 - 2⁶ = 667651620697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (667651620731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 74794061 + ... + 74802986.

It is an arithmetic number, because the mean of its divisors is an integer number (166950305568).

Almost surely, 2^667651620761 is an apocalyptic number.

It is an amenable number.

667651620761 is a deficient number, since it is larger than the sum of its proper divisors (149601511).

667651620761 is a wasteful number, since it uses less digits than its factorization.

667651620761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149601510.

The product of its (nonzero) digits is 3810240, while the sum is 53.

The spelling of 667651620761 in words is "six hundred sixty-seven billion, six hundred fifty-one million, six hundred twenty thousand, seven hundred sixty-one".