28785771 has 24 divisors (see below), whose sum is σ = 47664864. Its totient is φ = 16398720.

The previous prime is 28785769. The next prime is 28785787. The reversal of 28785771 is 17758782.

28785771 is a `hidden beast` number, since 2 + 8 + 78 + 577 + 1 = 666.

It is not a de Polignac number, because 28785771 - 2¹ = 28785769 is a prime.

It is a super-2 number, since 2×28785771² = 1657241224128882, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28785721) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 32385 + ... + 33261.

It is an arithmetic number, because the mean of its divisors is an integer number (1986036).

Almost surely, 2^28785771 is an apocalyptic number.

28785771 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

28785771 is a deficient number, since it is larger than the sum of its proper divisors (18879093).

28785771 is a wasteful number, since it uses less digits than its factorization.

28785771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1411 (or 1408 counting only the distinct ones).

The product of its digits is 219520, while the sum is 45.

The square root of 28785771 is about 5365.2372734111. The cubic root of 28785771 is about 306.4732840078.

It can be divided in two parts, 2878 and 5771, that added together give a square (8649 = 93²).

The spelling of 28785771 in words is "twenty-eight million, seven hundred eighty-five thousand, seven hundred seventy-one".