28812491 has 4 divisors (see below), whose sum is σ = 30065232. Its totient is φ = 27559752.

The previous prime is 28812437. The next prime is 28812503. The reversal of 28812491 is 19421882.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19421882 = 2 ⋅9710941.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28812491 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28812431) 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, 626336 + ... + 626381.

It is an arithmetic number, because the mean of its divisors is an integer number (7516308).

Almost surely, 2^28812491 is an apocalyptic number.

28812491 is a deficient number, since it is larger than the sum of its proper divisors (1252741).

28812491 is a wasteful number, since it uses less digits than its factorization.

28812491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1252740.

The product of its digits is 9216, while the sum is 35.

The square root of 28812491 is about 5367.7268000523. The cubic root of 28812491 is about 306.5680812334.

The spelling of 28812491 in words is "twenty-eight million, eight hundred twelve thousand, four hundred ninety-one".