28787945 has 24 divisors (see below), whose sum is σ = 37444680. Its totient is φ = 21231360.

The previous prime is 28787921. The next prime is 28787959. The reversal of 28787945 is 54978782.

It can be written as a sum of positive squares in 4 ways, for example, as 283024 + 28504921 = 532^2 + 5339^2 .

It is not a de Polignac number, because 28787945 - 2¹² = 28783849 is a prime.

It is a Smith number, since the sum of its digits (50) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 28787893 and 28787902.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 73811 + ... + 74199.

It is an arithmetic number, because the mean of its divisors is an integer number (1560195).

Almost surely, 2^28787945 is an apocalyptic number.

It is an amenable number.

28787945 is a deficient number, since it is larger than the sum of its proper divisors (8656735).

28787945 is a wasteful number, since it uses less digits than its factorization.

28787945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 473 (or 454 counting only the distinct ones).

The product of its digits is 1128960, while the sum is 50.

The square root of 28787945 is about 5365.4398701318. The cubic root of 28787945 is about 306.4809991175.

The spelling of 28787945 in words is "twenty-eight million, seven hundred eighty-seven thousand, nine hundred forty-five".