28764691 has 4 divisors (see below), whose sum is σ = 28809000. Its totient is φ = 28720384.

The previous prime is 28764677. The next prime is 28764709. The reversal of 28764691 is 19646782.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28764691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28764601) 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, 21166 + ... + 22483.

It is an arithmetic number, because the mean of its divisors is an integer number (7202250).

Almost surely, 2^28764691 is an apocalyptic number.

28764691 is a deficient number, since it is larger than the sum of its proper divisors (44309).

28764691 is an equidigital number, since it uses as much as digits as its factorization.

28764691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44308.

The product of its digits is 145152, while the sum is 43.

The square root of 28764691 is about 5363.2724152331. The cubic root of 28764691 is about 306.3984549718.

The spelling of 28764691 in words is "twenty-eight million, seven hundred sixty-four thousand, six hundred ninety-one".