212181552791 has 4 divisors (see below), whose sum is σ = 228503210712. Its totient is φ = 195859894872.

The previous prime is 212181552767. The next prime is 212181552797. The reversal of 212181552791 is 197255181212.

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

It is a cyclic number.

It is not a de Polignac number, because 212181552791 - 2³⁰ = 211107810967 is a prime.

It is a super-2 number, since 2×212181552791² (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 (212181552797) 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, 8160828941 + ... + 8160828966.

It is an arithmetic number, because the mean of its divisors is an integer number (57125802678).

Almost surely, 2^212181552791 is an apocalyptic number.

212181552791 is a deficient number, since it is larger than the sum of its proper divisors (16321657921).

212181552791 is a wasteful number, since it uses less digits than its factorization.

212181552791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16321657920.

The product of its digits is 100800, while the sum is 44.

The spelling of 212181552791 in words is "two hundred twelve billion, one hundred eighty-one million, five hundred fifty-two thousand, seven hundred ninety-one".