20672071221 has 4 divisors (see below), whose sum is σ = 27562761632. Its totient is φ = 13781380812.

The previous prime is 20672071181. The next prime is 20672071223. The reversal of 20672071221 is 12217027602.

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 20672071221 - 2⁶ = 20672071157 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 (20672071223) 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, 3445345201 + ... + 3445345206.

It is an arithmetic number, because the mean of its divisors is an integer number (6890690408).

Almost surely, 2^20672071221 is an apocalyptic number.

It is an amenable number.

20672071221 is a deficient number, since it is larger than the sum of its proper divisors (6890690411).

20672071221 is an equidigital number, since it uses as much as digits as its factorization.

20672071221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6890690410.

The product of its (nonzero) digits is 4704, while the sum is 30.

Adding to 20672071221 its reverse (12217027602), we get a palindrome (32889098823).

The spelling of 20672071221 in words is "twenty billion, six hundred seventy-two million, seventy-one thousand, two hundred twenty-one".