28400787 has 20 divisors (see below), whose sum is σ = 42569736. Its totient is φ = 18869760.

The previous prime is 28400777. The next prime is 28400789. The reversal of 28400787 is 78700482.

It is not a de Polignac number, because 28400787 - 2⁸ = 28400531 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28400789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 43987 + ... + 44627.

Almost surely, 2^28400787 is an apocalyptic number.

28400787 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

28400787 is a deficient number, since it is larger than the sum of its proper divisors (14168949).

28400787 is an equidigital number, since it uses as much as digits as its factorization.

28400787 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1200 (or 1191 counting only the distinct ones).

The product of its (nonzero) digits is 25088, while the sum is 36.

The square root of 28400787 is about 5329.2388762374. The cubic root of 28400787 is about 305.1008785720.

The spelling of 28400787 in words is "twenty-eight million, four hundred thousand, seven hundred eighty-seven".