28135357681 has 8 divisors (see below), whose sum is σ = 29620261280. Its totient is φ = 26650863648.

The previous prime is 28135357669. The next prime is 28135357687. The reversal of 28135357681 is 18675353182.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28135357681 is a prime.

It is a super-2 number, since 2×28135357681² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28135357687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 44005 + ... + 241261.

It is an arithmetic number, because the mean of its divisors is an integer number (3702532660).

Almost surely, 2^28135357681 is an apocalyptic number.

It is an amenable number.

28135357681 is a deficient number, since it is larger than the sum of its proper divisors (1484903599).

28135357681 is a wasteful number, since it uses less digits than its factorization.

28135357681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204783.

The product of its digits is 1209600, while the sum is 49.

The spelling of 28135357681 in words is "twenty-eight billion, one hundred thirty-five million, three hundred fifty-seven thousand, six hundred eighty-one".