671605212761 has 4 divisors (see below), whose sum is σ = 767548814592. Its totient is φ = 575661610932.

The previous prime is 671605212739. The next prime is 671605212851. The reversal of 671605212761 is 167212506176.

671605212761 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 671605212761 - 2¹⁸ = 671604950617 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (671605212961) 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, 47971800905 + ... + 47971800918.

It is an arithmetic number, because the mean of its divisors is an integer number (191887203648).

Almost surely, 2^671605212761 is an apocalyptic number.

It is an amenable number.

671605212761 is a deficient number, since it is larger than the sum of its proper divisors (95943601831).

671605212761 is an equidigital number, since it uses as much as digits as its factorization.

671605212761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95943601830.

The product of its (nonzero) digits is 211680, while the sum is 44.

The spelling of 671605212761 in words is "six hundred seventy-one billion, six hundred five million, two hundred twelve thousand, seven hundred sixty-one".