211671651671 has 4 divisors (see below), whose sum is σ = 212271288432. Its totient is φ = 211072014912.

The previous prime is 211671651589. The next prime is 211671651673. The reversal of 211671651671 is 176156176112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211671651671 is a prime.

It is a super-2 number, since 2×211671651671² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211671651673) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 299817851 + ... + 299818556.

It is an arithmetic number, because the mean of its divisors is an integer number (53067822108).

Almost surely, 2^211671651671 is an apocalyptic number.

211671651671 is a deficient number, since it is larger than the sum of its proper divisors (599636761).

211671651671 is an equidigital number, since it uses as much as digits as its factorization.

211671651671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 599636760.

The product of its digits is 105840, while the sum is 44.

The spelling of 211671651671 in words is "two hundred eleven billion, six hundred seventy-one million, six hundred fifty-one thousand, six hundred seventy-one".