2001011121 has 20 divisors (see below), whose sum is σ = 3038174964. Its totient is φ = 1312135200.

The previous prime is 2001011101. The next prime is 2001011123. The reversal of 2001011121 is 1211101002.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1008761121 + 992250000 = 31761^2 + 31500^2 .

It is not a de Polignac number, because 2001011121 - 2²⁷ = 1866793393 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (2001011123) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 197550 + ... + 207431.

Almost surely, 2^2001011121 is an apocalyptic number.

It is an amenable number.

2001011121 is a deficient number, since it is larger than the sum of its proper divisors (1037163843).

2001011121 is an equidigital number, since it uses as much as digits as its factorization.

2001011121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 405054 (or 405045 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

The square root of 2001011121 is about 44732.6627980048. The cubic root of 2001011121 is about 1260.1333362297.

Adding to 2001011121 its reverse (1211101002), we get a palindrome (3212112123).

The spelling of 2001011121 in words is "two billion, one million, eleven thousand, one hundred twenty-one".