28264309 has 4 divisors (see below), whose sum is σ = 29493216. Its totient is φ = 27035404.

The previous prime is 28264307. The next prime is 28264349. The reversal of 28264309 is 90346282.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28264309 - 2¹ = 28264307 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28264303) 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, 614419 + ... + 614464.

It is an arithmetic number, because the mean of its divisors is an integer number (7373304).

Almost surely, 2^28264309 is an apocalyptic number.

It is an amenable number.

28264309 is a deficient number, since it is larger than the sum of its proper divisors (1228907).

28264309 is a wasteful number, since it uses less digits than its factorization.

28264309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1228906.

The product of its (nonzero) digits is 20736, while the sum is 34.

The square root of 28264309 is about 5316.4188134495. The cubic root of 28264309 is about 304.6113799887.

The spelling of 28264309 in words is "twenty-eight million, two hundred sixty-four thousand, three hundred nine".