2145523220 has 12 divisors (see below), whose sum is σ = 4505598804. Its totient is φ = 858209280.

The previous prime is 2145523117. The next prime is 2145523223. The reversal of 2145523220 is 223255412.

It can be written as a sum of positive squares in 2 ways, for example, as 1076102416 + 1069420804 = 32804^2 + 32702^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 2145523220.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2145523223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53638061 + ... + 53638100.

It is an arithmetic number, because the mean of its divisors is an integer number (375466567).

Almost surely, 2^2145523220 is an apocalyptic number.

2145523220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2145523220 is an abundant number, since it is smaller than the sum of its proper divisors (2360075584).

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

2145523220 is a wasteful number, since it uses less digits than its factorization.

2145523220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107276170 (or 107276168 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 26.

The square root of 2145523220 is about 46319.7929615407. The cubic root of 2145523220 is about 1289.7664421022.

Adding to 2145523220 its reverse (223255412), we get a palindrome (2368778632).

The spelling of 2145523220 in words is "two billion, one hundred forty-five million, five hundred twenty-three thousand, two hundred twenty".