2001099520 has 72 divisors (see below), whose sum is σ = 5478034464. Its totient is φ = 686088192.

The previous prime is 2001099511. The next prime is 2001099577. The reversal of 2001099520 is 259901002.

It is a Harshad number since it is a multiple of its sum of digits (28).

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, 102709 + ... + 120628.

It is an arithmetic number, because the mean of its divisors is an integer number (76083812).

Almost surely, 2^2001099520 is an apocalyptic number.

2001099520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2001099520 is an abundant number, since it is smaller than the sum of its proper divisors (3476934944).

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

2001099520 is an equidigital number, since it uses as much as digits as its factorization.

2001099520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223365 (or 223351 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 28.

The square root of 2001099520 is about 44733.6508682222. The cubic root of 2001099520 is about 1260.1518923295.

The spelling of 2001099520 in words is "two billion, one million, ninety-nine thousand, five hundred twenty".