2001223520 has 48 divisors (see below), whose sum is σ = 4737162528. Its totient is φ = 798919680.

The previous prime is 2001223453. The next prime is 2001223529. The reversal of 2001223520 is 253221002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001223529) 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, 71357 + ... + 95363.

It is an arithmetic number, because the mean of its divisors is an integer number (98690886).

Almost surely, 2^2001223520 is an apocalyptic number.

2001223520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2001223520 is an abundant number, since it is smaller than the sum of its proper divisors (2735939008).

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

2001223520 is a wasteful number, since it uses less digits than its factorization.

2001223520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24543 (or 24535 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 2001223520 is about 44735.0368279719. The cubic root of 2001223520 is about 1260.1779206214.

Adding to 2001223520 its reverse (253221002), we get a palindrome (2254444522).

The spelling of 2001223520 in words is "two billion, one million, two hundred twenty-three thousand, five hundred twenty".