2155523020 has 96 divisors (see below), whose sum is σ = 5633510400. Its totient is φ = 675972864.

The previous prime is 2155523011. The next prime is 2155523021. The reversal of 2155523020 is 203255512.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (2155523021) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 63169 + ... + 91111.

It is an arithmetic number, because the mean of its divisors is an integer number (58682400).

Almost surely, 2^2155523020 is an apocalyptic number.

2155523020 is a gapful number since it is divisible by the number (20) 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 2155523020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2816755200).

2155523020 is an abundant number, since it is smaller than the sum of its proper divisors (3477987380).

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

2155523020 is a wasteful number, since it uses less digits than its factorization.

2155523020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28007 (or 28005 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 25.

The square root of 2155523020 is about 46427.6105351115. The cubic root of 2155523020 is about 1291.7671072964.

Adding to 2155523020 its reverse (203255512), we get a palindrome (2358778532).

The spelling of 2155523020 in words is "two billion, one hundred fifty-five million, five hundred twenty-three thousand, twenty".