2121771660 has 96 divisors (see below), whose sum is σ = 6312116160. Its totient is φ = 531514368.

The previous prime is 2121771653. The next prime is 2121771731. The reversal of 2121771660 is 661771212.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 47902 + ... + 80858.

It is an arithmetic number, because the mean of its divisors is an integer number (65751210).

Almost surely, 2^2121771660 is an apocalyptic number.

2121771660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2121771660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3156058080).

2121771660 is an abundant number, since it is smaller than the sum of its proper divisors (4190344500).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2121771660 is a wasteful number, since it uses less digits than its factorization.

2121771660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33035 (or 33033 counting only the distinct ones).

The product of its (nonzero) digits is 7056, while the sum is 33.

The square root of 2121771660 is about 46062.6927133011. The cubic root of 2121771660 is about 1284.9894087859.

The spelling of 2121771660 in words is "two billion, one hundred twenty-one million, seven hundred seventy-one thousand, six hundred sixty".