20644540711 has 4 divisors (see below), whose sum is σ = 20666204352. Its totient is φ = 20622877072.

The previous prime is 20644540667. The next prime is 20644540717. The reversal of 20644540711 is 11704544602.

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 20644540711 - 2¹⁹ = 20644016423 is a prime.

It is a super-2 number, since 2×20644540711² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20644540717) 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, 10830391 + ... + 10832296.

It is an arithmetic number, because the mean of its divisors is an integer number (5166551088).

Almost surely, 2^20644540711 is an apocalyptic number.

20644540711 is a deficient number, since it is larger than the sum of its proper divisors (21663641).

20644540711 is an equidigital number, since it uses as much as digits as its factorization.

20644540711 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21663640.

The product of its (nonzero) digits is 26880, while the sum is 34.

The spelling of 20644540711 in words is "twenty billion, six hundred forty-four million, five hundred forty thousand, seven hundred eleven".