2099129921 has 4 divisors (see below), whose sum is σ = 2399005632. Its totient is φ = 1799254212.

The previous prime is 2099129911. The next prime is 2099129993. The reversal of 2099129921 is 1299219902.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 2099129921 - 2¹⁴ = 2099113537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2099129911) 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, 149937845 + ... + 149937858.

It is an arithmetic number, because the mean of its divisors is an integer number (599751408).

Almost surely, 2^2099129921 is an apocalyptic number.

It is an amenable number.

2099129921 is a deficient number, since it is larger than the sum of its proper divisors (299875711).

2099129921 is an equidigital number, since it uses as much as digits as its factorization.

2099129921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299875710.

The product of its (nonzero) digits is 52488, while the sum is 44.

The square root of 2099129921 is about 45816.2626258406. The cubic root of 2099129921 is about 1280.4022826137.

The spelling of 2099129921 in words is "two billion, ninety-nine million, one hundred twenty-nine thousand, nine hundred twenty-one".