28723405 has 8 divisors (see below), whose sum is σ = 34953984. Its totient is φ = 22654800.

The previous prime is 28723367. The next prime is 28723423. The reversal of 28723405 is 50432782.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28723405 - 2¹⁹ = 28199117 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40101 + ... + 40810.

It is an arithmetic number, because the mean of its divisors is an integer number (4369248).

Almost surely, 2^28723405 is an apocalyptic number.

It is an amenable number.

28723405 is a deficient number, since it is larger than the sum of its proper divisors (6230579).

28723405 is an equidigital number, since it uses as much as digits as its factorization.

28723405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80987.

The product of its (nonzero) digits is 13440, while the sum is 31.

The square root of 28723405 is about 5359.4220770527. The cubic root of 28723405 is about 306.2517934089.

The spelling of 28723405 in words is "twenty-eight million, seven hundred twenty-three thousand, four hundred five".