20187551111 has 24 divisors (see below), whose sum is σ = 25667414640. Its totient is φ = 15734138112.

The previous prime is 20187551077. The next prime is 20187551161. The reversal of 20187551111 is 11115578102.

It is not a de Polignac number, because 20187551111 - 2²² = 20183356807 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20187551161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 193826 + ... + 279183.

It is an arithmetic number, because the mean of its divisors is an integer number (1069475610).

Almost surely, 2^20187551111 is an apocalyptic number.

20187551111 is a deficient number, since it is larger than the sum of its proper divisors (5479863529).

20187551111 is a wasteful number, since it uses less digits than its factorization.

20187551111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 473103 (or 473096 counting only the distinct ones).

The product of its (nonzero) digits is 2800, while the sum is 32.

The spelling of 20187551111 in words is "twenty billion, one hundred eighty-seven million, five hundred fifty-one thousand, one hundred eleven".