28720493 has 8 divisors (see below), whose sum is σ = 29057280. Its totient is φ = 28386000.

The previous prime is 28720487. The next prime is 28720507. The reversal of 28720493 is 39402782.

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 28720493 - 2¹⁶ = 28654957 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 (28720403) 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, 37868 + ... + 38618.

It is an arithmetic number, because the mean of its divisors is an integer number (3632160).

Almost surely, 2^28720493 is an apocalyptic number.

It is an amenable number.

28720493 is a deficient number, since it is larger than the sum of its proper divisors (336787).

28720493 is a wasteful number, since it uses less digits than its factorization.

28720493 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1147.

The product of its (nonzero) digits is 24192, while the sum is 35.

The square root of 28720493 is about 5359.1503990838. The cubic root of 28720493 is about 306.2414437149.

The spelling of 28720493 in words is "twenty-eight million, seven hundred twenty thousand, four hundred ninety-three".