2155440231 has 24 divisors (see below), whose sum is σ = 3640940160. Its totient is φ = 1203034896.

The previous prime is 2155440227. The next prime is 2155440253. The reversal of 2155440231 is 1320445512.

2155440231 is a `hidden beast` number, since 215 + 5 + 440 + 2 + 3 + 1 = 666.

It is not a de Polignac number, because 2155440231 - 2² = 2155440227 is a prime.

It is a super-2 number, since 2×2155440231² = 9291845178826666722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 2155440195 and 2155440204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2155440271) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 395121 + ... + 400538.

It is an arithmetic number, because the mean of its divisors is an integer number (151705840).

Almost surely, 2^2155440231 is an apocalyptic number.

2155440231 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

2155440231 is a deficient number, since it is larger than the sum of its proper divisors (1485499929).

2155440231 is a wasteful number, since it uses less digits than its factorization.

2155440231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 795715 (or 795712 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The square root of 2155440231 is about 46426.7189342516. The cubic root of 2155440231 is about 1291.7505690866.

Adding to 2155440231 its reverse (1320445512), we get a palindrome (3475885743).

The spelling of 2155440231 in words is "two billion, one hundred fifty-five million, four hundred forty thousand, two hundred thirty-one".