20738910221 has 4 divisors (see below), whose sum is σ = 20739845472. Its totient is φ = 20737974972.

The previous prime is 20738910211. The next prime is 20738910251. The reversal of 20738910221 is 12201983702.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12201983702 = 2 ⋅6100991851.

It is a cyclic number.

It is not a de Polignac number, because 20738910221 - 2¹⁰ = 20738909197 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20738910211) 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 3 ways as a sum of consecutive naturals, for example, 433535 + ... + 478988.

It is an arithmetic number, because the mean of its divisors is an integer number (5184961368).

Almost surely, 2^20738910221 is an apocalyptic number.

It is an amenable number.

20738910221 is a deficient number, since it is larger than the sum of its proper divisors (935251).

20738910221 is an equidigital number, since it uses as much as digits as its factorization.

20738910221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 935250.

The product of its (nonzero) digits is 12096, while the sum is 35.

The spelling of 20738910221 in words is "twenty billion, seven hundred thirty-eight million, nine hundred ten thousand, two hundred twenty-one".