28264509 has 24 divisors (see below), whose sum is σ = 50249472. Its totient is φ = 14908320.

The previous prime is 28264507. The next prime is 28264519. The reversal of 28264509 is 90546282.

28264509 = T₁₈₂ + T₁₈₃ + ... + T₅₅₉.

It is a happy number.

28264509 is a `hidden beast` number, since 2 + 8 + 2 + 645 + 0 + 9 = 666.

It is not a de Polignac number, because 28264509 - 2¹ = 28264507 is a prime.

It is a super-2 number, since 2×28264509² = 1597764938022162, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28264501) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16437 + ... + 18074.

It is an arithmetic number, because the mean of its divisors is an integer number (2093728).

Almost surely, 2^28264509 is an apocalyptic number.

It is an amenable number.

28264509 is a deficient number, since it is larger than the sum of its proper divisors (21984963).

28264509 is a wasteful number, since it uses less digits than its factorization.

28264509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34537 (or 34534 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 28264509 is about 5316.4376230705. The cubic root of 28264509 is about 304.6120984700.

The spelling of 28264509 in words is "twenty-eight million, two hundred sixty-four thousand, five hundred nine".