28309408 has 12 divisors (see below), whose sum is σ = 55734210. Its totient is φ = 14154688.

The previous prime is 28309399. The next prime is 28309409. The reversal of 28309408 is 80490382.

It can be written as a sum of positive squares in only one way, i.e., 27583504 + 725904 = 5252^2 + 852^2 .

It is not an unprimeable number, because it can be changed into a prime (28309409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 442303 + ... + 442366.

Almost surely, 2^28309408 is an apocalyptic number.

It is an amenable number.

28309408 is a deficient number, since it is larger than the sum of its proper divisors (27424802).

28309408 is an equidigital number, since it uses as much as digits as its factorization.

28309408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 884679 (or 884671 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 28309408 is about 5320.6586058495. The cubic root of 28309408 is about 304.7733082167.

The spelling of 28309408 in words is "twenty-eight million, three hundred nine thousand, four hundred eight".