28661977 has 4 divisors (see below), whose sum is σ = 28686820. Its totient is φ = 28637136.

The previous prime is 28661959. The next prime is 28661981. The reversal of 28661977 is 77916682.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 741321 + 27920656 = 861^2 + 5284^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28661977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28665977) 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, 10602 + ... + 13027.

It is an arithmetic number, because the mean of its divisors is an integer number (7171705).

Almost surely, 2^28661977 is an apocalyptic number.

It is an amenable number.

28661977 is a deficient number, since it is larger than the sum of its proper divisors (24843).

28661977 is a wasteful number, since it uses less digits than its factorization.

28661977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24842.

The product of its digits is 254016, while the sum is 46.

The square root of 28661977 is about 5353.6881679829. The cubic root of 28661977 is about 306.0333204492.

The spelling of 28661977 in words is "twenty-eight million, six hundred sixty-one thousand, nine hundred seventy-seven".