28787949 has 6 divisors (see below), whose sum is σ = 41582606. Its totient is φ = 19191960.

The previous prime is 28787921. The next prime is 28787959. The reversal of 28787949 is 94978782.

It can be written as a sum of positive squares in only one way, i.e., 27562500 + 1225449 = 5250^2 + 1107^2 .

It is not a de Polignac number, because 28787949 - 2⁵ = 28787917 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 28787895 and 28787904.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28787909) 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, 1599322 + ... + 1599339.

Almost surely, 2^28787949 is an apocalyptic number.

It is an amenable number.

28787949 is a deficient number, since it is larger than the sum of its proper divisors (12794657).

28787949 is a wasteful number, since it uses less digits than its factorization.

28787949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3198667 (or 3198664 counting only the distinct ones).

The product of its digits is 2032128, while the sum is 54.

The square root of 28787949 is about 5365.4402428878. The cubic root of 28787949 is about 306.4810133124.

The spelling of 28787949 in words is "twenty-eight million, seven hundred eighty-seven thousand, nine hundred forty-nine".