2155931435784 has 128 divisors (see below), whose sum is σ = 6286508236800. Its totient is φ = 603384337920.

The previous prime is 2155931435767. The next prime is 2155931435803. The reversal of 2155931435784 is 4875341395512.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2398249 + ... + 3172295.

It is an arithmetic number, because the mean of its divisors is an integer number (49113345600).

Almost surely, 2^{2155931435784} is an apocalyptic number.

2155931435784 is a gapful number since it is divisible by the number (24) 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 2155931435784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3143254118400).

2155931435784 is an abundant number, since it is smaller than the sum of its proper divisors (4130576801016).

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

2155931435784 is a wasteful number, since it uses less digits than its factorization.

2155931435784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 774403 (or 774399 counting only the distinct ones).

The product of its digits is 18144000, while the sum is 57.

The spelling of 2155931435784 in words is "two trillion, one hundred fifty-five billion, nine hundred thirty-one million, four hundred thirty-five thousand, seven hundred eighty-four".