28777231 has 8 divisors (see below), whose sum is σ = 33777440. Its totient is φ = 23999328.

The previous prime is 28777213. The next prime is 28777241. The reversal of 28777231 is 13277782.

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

It is a cyclic number.

It is not a de Polignac number, because 28777231 - 2¹⁷ = 28646159 is a prime.

It is a super-2 number, since 2×28777231² = 1656258048054722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28777201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55296 + ... + 55813.

It is an arithmetic number, because the mean of its divisors is an integer number (4222180).

Almost surely, 2^28777231 is an apocalyptic number.

28777231 is a deficient number, since it is larger than the sum of its proper divisors (5000209).

28777231 is a wasteful number, since it uses less digits than its factorization.

28777231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111153.

The product of its digits is 32928, while the sum is 37.

The square root of 28777231 is about 5364.4413502246. The cubic root of 28777231 is about 306.4429734223.

The spelling of 28777231 in words is "twenty-eight million, seven hundred seventy-seven thousand, two hundred thirty-one".