28458691 has 4 divisors (see below), whose sum is σ = 28471912. Its totient is φ = 28445472.

The previous prime is 28458667. The next prime is 28458737. The reversal of 28458691 is 19685482.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28458691 - 2¹¹ = 28456643 is a prime.

It is a super-3 number, since 3×28458691³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28458601) 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, 2550 + ... + 7963.

It is an arithmetic number, because the mean of its divisors is an integer number (7117978).

Almost surely, 2^28458691 is an apocalyptic number.

28458691 is a deficient number, since it is larger than the sum of its proper divisors (13221).

28458691 is a wasteful number, since it uses less digits than its factorization.

28458691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13220.

The product of its digits is 138240, while the sum is 43.

The square root of 28458691 is about 5334.6687807211. The cubic root of 28458691 is about 305.3080860761.

The spelling of 28458691 in words is "twenty-eight million, four hundred fifty-eight thousand, six hundred ninety-one".