2101121989 has 4 divisors (see below), whose sum is σ = 2129904556. Its totient is φ = 2072339424.

The previous prime is 2101121959. The next prime is 2101122017. The reversal of 2101121989 is 9891211012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 398321764 + 1702800225 = 19958^2 + 41265^2 .

It is a cyclic number.

It is not a de Polignac number, because 2101121989 - 2¹⁹ = 2100597701 is a prime.

It is a super-2 number, since 2×2101121989² = 8829427225318632242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2101121929) 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, 14391174 + ... + 14391319.

It is an arithmetic number, because the mean of its divisors is an integer number (532476139).

Almost surely, 2^2101121989 is an apocalyptic number.

It is an amenable number.

2101121989 is a deficient number, since it is larger than the sum of its proper divisors (28782567).

2101121989 is an equidigital number, since it uses as much as digits as its factorization.

2101121989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28782566.

The product of its (nonzero) digits is 2592, while the sum is 34.

The square root of 2101121989 is about 45837.9972184649. The cubic root of 2101121989 is about 1280.8071871984.

The spelling of 2101121989 in words is "two billion, one hundred one million, one hundred twenty-one thousand, nine hundred eighty-nine".