20815706111 has 4 divisors (see below), whose sum is σ = 20821808472. Its totient is φ = 20809603752.

The previous prime is 20815706099. The next prime is 20815706113. The reversal of 20815706111 is 11160751802.

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 20815706111 - 2⁶ = 20815706047 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20815706113) 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, 3046061 + ... + 3052886.

It is an arithmetic number, because the mean of its divisors is an integer number (5205452118).

Almost surely, 2^20815706111 is an apocalyptic number.

20815706111 is a deficient number, since it is larger than the sum of its proper divisors (6102361).

20815706111 is an equidigital number, since it uses as much as digits as its factorization.

20815706111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6102360.

The product of its (nonzero) digits is 3360, while the sum is 32.

The spelling of 20815706111 in words is "twenty billion, eight hundred fifteen million, seven hundred six thousand, one hundred eleven".