20643631111 has 2 divisors, whose sum is σ = 20643631112. Its totient is φ = 20643631110.

The previous prime is 20643631061. The next prime is 20643631133. The reversal of 20643631111 is 11113634602.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20643631111 - 2⁷ = 20643630983 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20643631111.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20643631181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10321815555 + 10321815556.

It is an arithmetic number, because the mean of its divisors is an integer number (10321815556).

Almost surely, 2^20643631111 is an apocalyptic number.

20643631111 is a deficient number, since it is larger than the sum of its proper divisors (1).

20643631111 is an equidigital number, since it uses as much as digits as its factorization.

20643631111 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 28.

The spelling of 20643631111 in words is "twenty billion, six hundred forty-three million, six hundred thirty-one thousand, one hundred eleven".