212066651661 has 16 divisors (see below), whose sum is σ = 307238615040. Its totient is φ = 129616288560.

The previous prime is 212066651659. The next prime is 212066651681. The reversal of 212066651661 is 166156660212.

It is not a de Polignac number, because 212066651661 - 2¹ = 212066651659 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212066651681) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60005775 + ... + 60009308.

It is an arithmetic number, because the mean of its divisors is an integer number (19202413440).

Almost surely, 2^212066651661 is an apocalyptic number.

It is an amenable number.

212066651661 is a deficient number, since it is larger than the sum of its proper divisors (95171963379).

212066651661 is a wasteful number, since it uses less digits than its factorization.

212066651661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120015136.

The product of its (nonzero) digits is 155520, while the sum is 42.

The spelling of 212066651661 in words is "two hundred twelve billion, sixty-six million, six hundred fifty-one thousand, six hundred sixty-one".