2156661884 has 48 divisors (see below), whose sum is σ = 4289060160. Its totient is φ = 941360640.

The previous prime is 2156661863. The next prime is 2156661887. The reversal of 2156661884 is 4881666512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2156661887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 96314 + ... + 116574.

It is an arithmetic number, because the mean of its divisors is an integer number (89355420).

Almost surely, 2^2156661884 is an apocalyptic number.

It is an amenable number.

2156661884 is a deficient number, since it is larger than the sum of its proper divisors (2132398276).

2156661884 is a wasteful number, since it uses less digits than its factorization.

2156661884 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20390 (or 20388 counting only the distinct ones).

The product of its digits is 552960, while the sum is 47.

The square root of 2156661884 is about 46439.8738585711. The cubic root of 2156661884 is about 1291.9945676429.

The spelling of 2156661884 in words is "two billion, one hundred fifty-six million, six hundred sixty-one thousand, eight hundred eighty-four".