28697551191 has 36 divisors (see below), whose sum is σ = 43738393608. Its totient is φ = 18128538912.

The previous prime is 28697551177. The next prime is 28697551213. The reversal of 28697551191 is 19115579682.

It is a happy number.

28697551191 is a `hidden beast` number, since 2 + 86 + 9 + 7 + 551 + 1 + 9 + 1 = 666.

It is not a de Polignac number, because 28697551191 - 2²⁶ = 28630442327 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28697551591) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 481261 + ... + 537593.

It is an arithmetic number, because the mean of its divisors is an integer number (1214955378).

Almost surely, 2^28697551191 is an apocalyptic number.

28697551191 is a deficient number, since it is larger than the sum of its proper divisors (15040842417).

28697551191 is a wasteful number, since it uses less digits than its factorization.

28697551191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56492 (or 56466 counting only the distinct ones).

The product of its digits is 1360800, while the sum is 54.

The spelling of 28697551191 in words is "twenty-eight billion, six hundred ninety-seven million, five hundred fifty-one thousand, one hundred ninety-one".