28839661 has 6 divisors (see below), whose sum is σ = 29215662. Its totient is φ = 28468440.

The previous prime is 28839647. The next prime is 28839673. The reversal of 28839661 is 16693882.

It can be written as a sum of positive squares in only one way, i.e., 23222761 + 5616900 = 4819^2 + 2370^2 .

It is not a de Polignac number, because 28839661 - 2⁷ = 28839533 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28839611) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3931 + ... + 8551.

It is an arithmetic number, because the mean of its divisors is an integer number (4869277).

Almost surely, 2^28839661 is an apocalyptic number.

It is an amenable number.

28839661 is a deficient number, since it is larger than the sum of its proper divisors (376001).

28839661 is an frugal number, since it uses more digits than its factorization.

28839661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4779 (or 4700 counting only the distinct ones).

The product of its digits is 124416, while the sum is 43.

The square root of 28839661 is about 5370.2570701969. The cubic root of 28839661 is about 306.6644148910.

It can be divided in two parts, 2883 and 9661, that added together give a square (12544 = 112²).

The spelling of 28839661 in words is "twenty-eight million, eight hundred thirty-nine thousand, six hundred sixty-one".