20000019921 has 8 divisors (see below), whose sum is σ = 30476220864. Its totient is φ = 11428582800.

The previous prime is 20000019901. The next prime is 20000019961. The reversal of 20000019921 is 12991000002.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20000019921 - 2⁹ = 20000019409 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20000019891 and 20000019900.

It is not an unprimeable number, because it can be changed into a prime (20000019901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 476190930 + ... + 476190971.

It is an arithmetic number, because the mean of its divisors is an integer number (3809527608).

Almost surely, 2^20000019921 is an apocalyptic number.

20000019921 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20000019921 is a deficient number, since it is larger than the sum of its proper divisors (10476200943).

20000019921 is an equidigital number, since it uses as much as digits as its factorization.

20000019921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 952381911.

The product of its (nonzero) digits is 324, while the sum is 24.

Adding to 20000019921 its reverse (12991000002), we get a palindrome (32991019923).

The spelling of 20000019921 in words is "twenty billion, nineteen thousand, nine hundred twenty-one".