20098921 has 4 divisors (see below), whose sum is σ = 20167812. Its totient is φ = 20030032.

The previous prime is 20098909. The next prime is 20098927. The reversal of 20098921 is 12989002.

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 11128896 + 8970025 = 3336^2 + 2995^2 .

It is a cyclic number.

It is not a de Polignac number, because 20098921 - 2⁵ = 20098889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20098927) 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, 34006 + ... + 34591.

It is an arithmetic number, because the mean of its divisors is an integer number (5041953).

Almost surely, 2^20098921 is an apocalyptic number.

It is an amenable number.

20098921 is a deficient number, since it is larger than the sum of its proper divisors (68891).

20098921 is an equidigital number, since it uses as much as digits as its factorization.

20098921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68890.

The product of its (nonzero) digits is 2592, while the sum is 31.

The square root of 20098921 is about 4483.1820172730. The cubic root of 20098921 is about 271.8885473674. Note that the first 3 decimals are identical.

The spelling of 20098921 in words is "twenty million, ninety-eight thousand, nine hundred twenty-one".