671721651165 has 32 divisors (see below), whose sum is σ = 1078642832256. Its totient is φ = 356956532480.

The previous prime is 671721651089. The next prime is 671721651179. The reversal of 671721651165 is 561156127176.

It is not a de Polignac number, because 671721651165 - 2²⁴ = 671704873949 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10633975 + ... + 10696955.

It is an arithmetic number, because the mean of its divisors is an integer number (33707588508).

Almost surely, 2^671721651165 is an apocalyptic number.

It is an amenable number.

671721651165 is a deficient number, since it is larger than the sum of its proper divisors (406921181091).

671721651165 is a wasteful number, since it uses less digits than its factorization.

671721651165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65549.

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

The spelling of 671721651165 in words is "six hundred seventy-one billion, seven hundred twenty-one million, six hundred fifty-one thousand, one hundred sixty-five".