2155839868 has 72 divisors (see below), whose sum is σ = 4744659024. Its totient is φ = 849542400.

The previous prime is 2155839827. The next prime is 2155839893. The reversal of 2155839868 is 8689385512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 714483 + ... + 717493.

It is an arithmetic number, because the mean of its divisors is an integer number (65898042).

Almost surely, 2^2155839868 is an apocalyptic number.

2155839868 is a gapful number since it is divisible by the number (28) 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 2155839868, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2372329512).

2155839868 is an abundant number, since it is smaller than the sum of its proper divisors (2588819156).

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

2155839868 is a wasteful number, since it uses less digits than its factorization.

2155839868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3323 (or 3314 counting only the distinct ones).

The product of its digits is 4147200, while the sum is 55.

The square root of 2155839868 is about 46431.0226895768. The cubic root of 2155839868 is about 1291.8303980102.

The spelling of 2155839868 in words is "two billion, one hundred fifty-five million, eight hundred thirty-nine thousand, eight hundred sixty-eight".