2121666677 has 4 divisors (see below), whose sum is σ = 2284871820. Its totient is φ = 1958461536.

The previous prime is 2121666653. The next prime is 2121666683. The reversal of 2121666677 is 7766661212.

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

It can be written as a sum of positive squares in 2 ways, for example, as 645109201 + 1476557476 = 25399^2 + 38426^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121666677 - 2¹⁰ = 2121665653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121666077) 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 3 ways as a sum of consecutive naturals, for example, 81602552 + ... + 81602577.

It is an arithmetic number, because the mean of its divisors is an integer number (571217955).

Almost surely, 2^2121666677 is an apocalyptic number.

It is an amenable number.

2121666677 is a deficient number, since it is larger than the sum of its proper divisors (163205143).

2121666677 is a wasteful number, since it uses less digits than its factorization.

2121666677 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163205142.

The product of its digits is 254016, while the sum is 44.

The square root of 2121666677 is about 46061.5531327375. The cubic root of 2121666677 is about 1284.9682151343.

The spelling of 2121666677 in words is "two billion, one hundred twenty-one million, six hundred sixty-six thousand, six hundred seventy-seven".