28697668261 has 16 divisors (see below), whose sum is σ = 31776465024. Its totient is φ = 25778548224.

The previous prime is 28697668253. The next prime is 28697668277. The reversal of 28697668261 is 16286679682.

It is a cyclic number.

It is not a de Polignac number, because 28697668261 - 2³ = 28697668253 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28697668261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28697668201) 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, 98386 + ... + 258988.

It is an arithmetic number, because the mean of its divisors is an integer number (1986029064).

Almost surely, 2^28697668261 is an apocalyptic number.

It is an amenable number.

28697668261 is a deficient number, since it is larger than the sum of its proper divisors (3078796763).

28697668261 is a wasteful number, since it uses less digits than its factorization.

28697668261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161100.

The product of its digits is 20901888, while the sum is 61.

The spelling of 28697668261 in words is "twenty-eight billion, six hundred ninety-seven million, six hundred sixty-eight thousand, two hundred sixty-one".