20803453921 has 4 divisors (see below), whose sum is σ = 20997878832. Its totient is φ = 20609029012.

The previous prime is 20803453901. The next prime is 20803453939. The reversal of 20803453921 is 12935430802.

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 a cyclic number.

It is not a de Polignac number, because 20803453921 - 2⁵ = 20803453889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20803453901) 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, 97212295 + ... + 97212508.

It is an arithmetic number, because the mean of its divisors is an integer number (5249469708).

Almost surely, 2^20803453921 is an apocalyptic number.

It is an amenable number.

20803453921 is a deficient number, since it is larger than the sum of its proper divisors (194424911).

20803453921 is a wasteful number, since it uses less digits than its factorization.

20803453921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194424910.

The product of its (nonzero) digits is 51840, while the sum is 37.

The spelling of 20803453921 in words is "twenty billion, eight hundred three million, four hundred fifty-three thousand, nine hundred twenty-one".