671305615765 has 4 divisors (see below), whose sum is σ = 805566738924. Its totient is φ = 537044492608.

The previous prime is 671305615763. The next prime is 671305615787. The reversal of 671305615765 is 567516503176.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 354641688324 + 316663927441 = 595518^2 + 562729^2 .

It is a cyclic number.

It is not a de Polignac number, because 671305615765 - 2¹ = 671305615763 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 (671305615763) 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, 67130561572 + ... + 67130561581.

It is an arithmetic number, because the mean of its divisors is an integer number (201391684731).

Almost surely, 2^671305615765 is an apocalyptic number.

It is an amenable number.

671305615765 is a deficient number, since it is larger than the sum of its proper divisors (134261123159).

671305615765 is a wasteful number, since it uses less digits than its factorization.

671305615765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134261123158.

The product of its (nonzero) digits is 3969000, while the sum is 52.

The spelling of 671305615765 in words is "six hundred seventy-one billion, three hundred five million, six hundred fifteen thousand, seven hundred sixty-five".