2155423440 has 40 divisors (see below), whose sum is σ = 6681813408. Its totient is φ = 574779520.

The previous prime is 2155423429. The next prime is 2155423513. The reversal of 2155423440 is 443245512.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 2155423398 and 2155423407.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4490226 + ... + 4490705.

Almost surely, 2^2155423440 is an apocalyptic number.

2155423440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2155423440 is an abundant number, since it is smaller than the sum of its proper divisors (4526389968).

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

2155423440 is a wasteful number, since it uses less digits than its factorization.

2155423440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8980947 (or 8980941 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 30.

The square root of 2155423440 is about 46426.5381005304. The cubic root of 2155423440 is about 1291.7472148081.

Adding to 2155423440 its reverse (443245512), we get a palindrome (2598668952).

The spelling of 2155423440 in words is "two billion, one hundred fifty-five million, four hundred twenty-three thousand, four hundred forty".