2171871686 has 16 divisors (see below), whose sum is σ = 3474629136. Its totient is φ = 1014594816.

The previous prime is 2171871677. The next prime is 2171871697. The reversal of 2171871686 is 6861781712.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 2171871686.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 228476 + ... + 237791.

It is an arithmetic number, because the mean of its divisors is an integer number (217164321).

Almost surely, 2^2171871686 is an apocalyptic number.

2171871686 is a deficient number, since it is larger than the sum of its proper divisors (1302757450).

2171871686 is a wasteful number, since it uses less digits than its factorization.

2171871686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 466423.

The product of its digits is 225792, while the sum is 47.

The square root of 2171871686 is about 46603.3441503933. The cubic root of 2171871686 is about 1295.0247081644.

The spelling of 2171871686 in words is "two billion, one hundred seventy-one million, eight hundred seventy-one thousand, six hundred eighty-six".