28917890 has 8 divisors (see below), whose sum is σ = 52052220. Its totient is φ = 11567152.

The previous prime is 28917883. The next prime is 28917893. The reversal of 28917890 is 9871982.

It can be written as a sum of positive squares in 2 ways, for example, as 26759929 + 2157961 = 5173^2 + 1469^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28917893) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1445885 + ... + 1445904.

Almost surely, 2^28917890 is an apocalyptic number.

28917890 is a deficient number, since it is larger than the sum of its proper divisors (23134330).

28917890 is a wasteful number, since it uses less digits than its factorization.

28917890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2891796.

The product of its (nonzero) digits is 72576, while the sum is 44.

The square root of 28917890 is about 5377.5356809602. The cubic root of 28917890 is about 306.9414453289.

The spelling of 28917890 in words is "twenty-eight million, nine hundred seventeen thousand, eight hundred ninety".