28780404 has 12 divisors (see below), whose sum is σ = 67154304. Its totient is φ = 9593464.

The previous prime is 28780397. The next prime is 28780417. The reversal of 28780404 is 40408782.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-4 number, since 4×28780404⁴ (a number of 31 digits) contains 4444 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1199172 + ... + 1199195.

It is an arithmetic number, because the mean of its divisors is an integer number (5596192).

Almost surely, 2^28780404 is an apocalyptic number.

It is an amenable number.

28780404 is an abundant number, since it is smaller than the sum of its proper divisors (38373900).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28780404 is a wasteful number, since it uses less digits than its factorization.

28780404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2398374 (or 2398372 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 33.

The square root of 28780404 is about 5364.7370858226. The cubic root of 28780404 is about 306.4542358890.

The spelling of 28780404 in words is "twenty-eight million, seven hundred eighty thousand, four hundred four".