28764217 has 4 divisors (see below), whose sum is σ = 28776676. Its totient is φ = 28751760.

The previous prime is 28764199. The next prime is 28764223. The reversal of 28764217 is 71246782.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 12313081 + 16451136 = 3509^2 + 4056^2 .

It is a cyclic number.

It is not a de Polignac number, because 28764217 - 2¹¹ = 28762169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28764227) 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, 1638 + ... + 7759.

It is an arithmetic number, because the mean of its divisors is an integer number (7194169).

Almost surely, 2^28764217 is an apocalyptic number.

It is an amenable number.

28764217 is a deficient number, since it is larger than the sum of its proper divisors (12459).

28764217 is an equidigital number, since it uses as much as digits as its factorization.

28764217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12458.

The product of its digits is 37632, while the sum is 37.

The square root of 28764217 is about 5363.2282256119. The cubic root of 28764217 is about 306.3967719632.

The spelling of 28764217 in words is "twenty-eight million, seven hundred sixty-four thousand, two hundred seventeen".