20767921791 has 8 divisors (see below), whose sum is σ = 28583806464. Its totient is φ = 13398659160.

The previous prime is 20767921787. The next prime is 20767921813. The reversal of 20767921791 is 19712976702.

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

It is not a de Polignac number, because 20767921791 - 2² = 20767921787 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20767921781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 111655401 + ... + 111655586.

It is an arithmetic number, because the mean of its divisors is an integer number (3572975808).

Almost surely, 2^20767921791 is an apocalyptic number.

20767921791 is a deficient number, since it is larger than the sum of its proper divisors (7815884673).

20767921791 is a wasteful number, since it uses less digits than its factorization.

20767921791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 223311021.

The product of its (nonzero) digits is 666792, while the sum is 51.

The spelling of 20767921791 in words is "twenty billion, seven hundred sixty-seven million, nine hundred twenty-one thousand, seven hundred ninety-one".