28685702137 has 4 divisors (see below), whose sum is σ = 28686047860. Its totient is φ = 28685356416.

The previous prime is 28685702117. The next prime is 28685702141. The reversal of 28685702137 is 73120758682.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 19614282601 + 9071419536 = 140051^2 + 95244^2 .

It is a 3-Lehmer number, since φ(28685702137) divides (28685702137-1)³.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28685702137 is a prime.

It is a deceptive number, since it divides R_28685702136.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28685702117) 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, 34573 + ... + 242005.

It is an arithmetic number, because the mean of its divisors is an integer number (7171511965).

Almost surely, 2^28685702137 is an apocalyptic number.

28685702137 is the 138289-th pentagonal number.

It is an amenable number.

28685702137 is a deficient number, since it is larger than the sum of its proper divisors (345723).

28685702137 is a wasteful number, since it uses less digits than its factorization.

28685702137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 345722.

The product of its (nonzero) digits is 1128960, while the sum is 49.

The spelling of 28685702137 in words is "twenty-eight billion, six hundred eighty-five million, seven hundred two thousand, one hundred thirty-seven".