20767211921 has 2 divisors, whose sum is σ = 20767211922. Its totient is φ = 20767211920.

The previous prime is 20767211909. The next prime is 20767211947. The reversal of 20767211921 is 12911276702.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12959545600 + 7807666321 = 113840^2 + 88361^2 .

It is a cyclic number.

It is not a de Polignac number, because 20767211921 - 2²² = 20763017617 is a prime.

It is not a weakly prime, because it can be changed into another prime (20767241921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10383605960 + 10383605961.

It is an arithmetic number, because the mean of its divisors is an integer number (10383605961).

Almost surely, 2^20767211921 is an apocalyptic number.

It is an amenable number.

20767211921 is a deficient number, since it is larger than the sum of its proper divisors (1).

20767211921 is an equidigital number, since it uses as much as digits as its factorization.

20767211921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21168, while the sum is 38.

The spelling of 20767211921 in words is "twenty billion, seven hundred sixty-seven million, two hundred eleven thousand, nine hundred twenty-one".