28012009 has 8 divisors (see below), whose sum is σ = 28356608. Its totient is φ = 27669600.

The previous prime is 28011989. The next prime is 28012031. The reversal of 28012009 is 90021082.

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

It is a cyclic number.

It is not a de Polignac number, because 28012009 - 2⁹ = 28011497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28012109) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46309 + ... + 46909.

It is an arithmetic number, because the mean of its divisors is an integer number (3544576).

Almost surely, 2^28012009 is an apocalyptic number.

It is an amenable number.

28012009 is a deficient number, since it is larger than the sum of its proper divisors (344599).

28012009 is a wasteful number, since it uses less digits than its factorization.

28012009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1095.

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 28012009 is about 5292.6372443235. The cubic root of 28012009 is about 303.7023033600.

The spelling of 28012009 in words is "twenty-eight million, twelve thousand, nine".