212065721655 has 32 divisors (see below), whose sum is σ = 359754727104. Its totient is φ = 106303358976.

The previous prime is 212065721653. The next prime is 212065721671. The reversal of 212065721655 is 556127560212.

It is not a de Polignac number, because 212065721655 - 2¹ = 212065721653 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212065721653) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 380364 + ... + 754193.

It is an arithmetic number, because the mean of its divisors is an integer number (11242335222).

Almost surely, 2^212065721655 is an apocalyptic number.

212065721655 is a deficient number, since it is larger than the sum of its proper divisors (147689005449).

212065721655 is a wasteful number, since it uses less digits than its factorization.

212065721655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1135315.

The product of its (nonzero) digits is 252000, while the sum is 42.

The spelling of 212065721655 in words is "two hundred twelve billion, sixty-five million, seven hundred twenty-one thousand, six hundred fifty-five".