211666570661 has 8 divisors (see below), whose sum is σ = 260512702464. Its totient is φ = 167472451440.

The previous prime is 211666570651. The next prime is 211666570711. The reversal of 211666570661 is 166075666112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-211666570661 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211666570651) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1163003045 + ... + 1163003226.

It is an arithmetic number, because the mean of its divisors is an integer number (32564087808).

Almost surely, 2^211666570661 is an apocalyptic number.

It is an amenable number.

211666570661 is a deficient number, since it is larger than the sum of its proper divisors (48846131803).

211666570661 is a wasteful number, since it uses less digits than its factorization.

211666570661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2326006291.

The product of its (nonzero) digits is 544320, while the sum is 47.

The spelling of 211666570661 in words is "two hundred eleven billion, six hundred sixty-six million, five hundred seventy thousand, six hundred sixty-one".