671571516261 has 4 divisors (see below), whose sum is σ = 895428688352. Its totient is φ = 447714344172.

The previous prime is 671571516257. The next prime is 671571516313. The reversal of 671571516261 is 162615175176.

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 not a de Polignac number, because 671571516261 - 2² = 671571516257 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 671571516261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (671571516211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111928586041 + ... + 111928586046.

It is an arithmetic number, because the mean of its divisors is an integer number (223857172088).

Almost surely, 2^671571516261 is an apocalyptic number.

It is an amenable number.

671571516261 is a deficient number, since it is larger than the sum of its proper divisors (223857172091).

671571516261 is a wasteful number, since it uses less digits than its factorization.

671571516261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223857172090.

The product of its digits is 529200, while the sum is 48.

The spelling of 671571516261 in words is "six hundred seventy-one billion, five hundred seventy-one million, five hundred sixteen thousand, two hundred sixty-one".