28856937691 has 16 divisors (see below), whose sum is σ = 30969207360. Its totient is φ = 26792570880.

The previous prime is 28856937643. The next prime is 28856937731. The reversal of 28856937691 is 19673965882.

It is a cyclic number.

It is not a de Polignac number, because 28856937691 - 2⁷ = 28856937563 is a prime.

It is a super-2 number, since 2×28856937691² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28856937191) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 484705 + ... + 540973.

It is an arithmetic number, because the mean of its divisors is an integer number (1935575460).

Almost surely, 2^28856937691 is an apocalyptic number.

28856937691 is a deficient number, since it is larger than the sum of its proper divisors (2112269669).

28856937691 is a wasteful number, since it uses less digits than its factorization.

28856937691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56694.

The product of its digits is 39191040, while the sum is 64.

The spelling of 28856937691 in words is "twenty-eight billion, eight hundred fifty-six million, nine hundred thirty-seven thousand, six hundred ninety-one".