671206156236721 has 16 divisors (see below), whose sum is σ = 771130717061760. Its totient is φ = 572298963586560.

The previous prime is 671206156236713. The next prime is 671206156236769. The reversal of 671206156236721 is 127632651602176.

It is a happy number.

It is not a de Polignac number, because 671206156236721 - 2³ = 671206156236713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (671206156236521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 327160576 + ... + 329205793.

It is an arithmetic number, because the mean of its divisors is an integer number (48195669816360).

Almost surely, 2^{671206156236721} is an apocalyptic number.

It is an amenable number.

671206156236721 is a deficient number, since it is larger than the sum of its proper divisors (99924560825039).

671206156236721 is a wasteful number, since it uses less digits than its factorization.

671206156236721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 656367144.

The product of its (nonzero) digits is 7620480, while the sum is 55.

The spelling of 671206156236721 in words is "six hundred seventy-one trillion, two hundred six billion, one hundred fifty-six million, two hundred thirty-six thousand, seven hundred twenty-one".