670856891691 has 64 divisors (see below), whose sum is σ = 1054582031360. Its totient is φ = 371322040320.

The previous prime is 670856891671. The next prime is 670856891737. The reversal of 670856891691 is 196198658076.

It is a de Polignac number, because none of the positive numbers 2^k-670856891691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (670856891671) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 181457955 + ... + 181461651.

It is an arithmetic number, because the mean of its divisors is an integer number (16477844240).

Almost surely, 2^670856891691 is an apocalyptic number.

670856891691 is a deficient number, since it is larger than the sum of its proper divisors (383725139669).

670856891691 is a wasteful number, since it uses less digits than its factorization.

670856891691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4724.

The product of its (nonzero) digits is 39191040, while the sum is 66.

The spelling of 670856891691 in words is "six hundred seventy billion, eight hundred fifty-six million, eight hundred ninety-one thousand, six hundred ninety-one".