2155440012 has 24 divisors (see below), whose sum is σ = 5486574912. Its totient is φ = 653163600.

The previous prime is 2155439999. The next prime is 2155440017. The reversal of 2155440012 is 2100445512.

It is not an unprimeable number, because it can be changed into a prime (2155440017) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8164414 + ... + 8164677.

It is an arithmetic number, because the mean of its divisors is an integer number (228607288).

Almost surely, 2^2155440012 is an apocalyptic number.

2155440012 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

2155440012 is an abundant number, since it is smaller than the sum of its proper divisors (3331134900).

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

2155440012 is a wasteful number, since it uses less digits than its factorization.

2155440012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16329109 (or 16329107 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 24.

The square root of 2155440012 is about 46426.7165756959. The cubic root of 2155440012 is about 1291.7505253378.

Adding to 2155440012 its reverse (2100445512), we get a palindrome (4255885524).

The spelling of 2155440012 in words is "two billion, one hundred fifty-five million, four hundred forty thousand, twelve".