20767212643 has 4 divisors (see below), whose sum is σ = 20767549600. Its totient is φ = 20766875688.

The previous prime is 20767212607. The next prime is 20767212673. The reversal of 20767212643 is 34621276702.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20767212643 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20767212596 and 20767212605.

It is not an unprimeable number, because it can be changed into a prime (20767212673) 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, 46680 + ... + 209077.

It is an arithmetic number, because the mean of its divisors is an integer number (5191887400).

Almost surely, 2^20767212643 is an apocalyptic number.

20767212643 is a deficient number, since it is larger than the sum of its proper divisors (336957).

20767212643 is an equidigital number, since it uses as much as digits as its factorization.

20767212643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 336956.

The product of its (nonzero) digits is 169344, while the sum is 40.

It can be divided in two parts, 2076721 and 2643, that added together give a square (2079364 = 1442²).

The spelling of 20767212643 in words is "twenty billion, seven hundred sixty-seven million, two hundred twelve thousand, six hundred forty-three".