20720511943 has 4 divisors (see below), whose sum is σ = 20720844808. Its totient is φ = 20720179080.

The previous prime is 20720511923. The next prime is 20720511971. The reversal of 20720511943 is 34911502702.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 20720511943 - 2¹⁷ = 20720380871 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20720511899 and 20720511908.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20720511923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42096 + ... + 207877.

It is an arithmetic number, because the mean of its divisors is an integer number (5180211202).

Almost surely, 2^20720511943 is an apocalyptic number.

20720511943 is a deficient number, since it is larger than the sum of its proper divisors (332865).

20720511943 is an equidigital number, since it uses as much as digits as its factorization.

20720511943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 332864.

The product of its (nonzero) digits is 15120, while the sum is 34.

The spelling of 20720511943 in words is "twenty billion, seven hundred twenty million, five hundred eleven thousand, nine hundred forty-three".