20767211221 has 4 divisors (see below), whose sum is σ = 21670133472. Its totient is φ = 19864288972.

The previous prime is 20767211219. The next prime is 20767211239. The reversal of 20767211221 is 12211276702.

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 20767211221 - 2¹ = 20767211219 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 (20767211921) 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, 451461091 + ... + 451461136.

It is an arithmetic number, because the mean of its divisors is an integer number (5417533368).

Almost surely, 2^20767211221 is an apocalyptic number.

It is an amenable number.

20767211221 is a deficient number, since it is larger than the sum of its proper divisors (902922251).

20767211221 is an equidigital number, since it uses as much as digits as its factorization.

20767211221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 902922250.

The product of its (nonzero) digits is 4704, while the sum is 31.

Adding to 20767211221 its reverse (12211276702), we get a palindrome (32978487923).

The spelling of 20767211221 in words is "twenty billion, seven hundred sixty-seven million, two hundred eleven thousand, two hundred twenty-one".