212440306661 has 16 divisors (see below), whose sum is σ = 234677314368. Its totient is φ = 190693296000.

The previous prime is 212440306643. The next prime is 212440306681. The reversal of 212440306661 is 166603044212.

It is a cyclic number.

It is not a de Polignac number, because 212440306661 - 2¹⁴ = 212440290277 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212440306601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1579715 + ... + 1708911.

It is an arithmetic number, because the mean of its divisors is an integer number (14667332148).

Almost surely, 2^212440306661 is an apocalyptic number.

It is an amenable number.

212440306661 is a deficient number, since it is larger than the sum of its proper divisors (22237007707).

212440306661 is a wasteful number, since it uses less digits than its factorization.

212440306661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131092.

The product of its (nonzero) digits is 41472, while the sum is 35.

The spelling of 212440306661 in words is "two hundred twelve billion, four hundred forty million, three hundred six thousand, six hundred sixty-one".