28691087 has 8 divisors (see below), whose sum is σ = 30664656. Its totient is φ = 26749312.

The previous prime is 28691081. The next prime is 28691093. The reversal of 28691087 is 78019682.

It is an interprime number because it is at equal distance from previous prime (28691081) and next prime (28691093).

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 28691087 - 2⁴ = 28691071 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 (28691081) 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, 6068 + ... + 9705.

It is an arithmetic number, because the mean of its divisors is an integer number (3833082).

Almost surely, 2^28691087 is an apocalyptic number.

28691087 is a deficient number, since it is larger than the sum of its proper divisors (1973569).

28691087 is a wasteful number, since it uses less digits than its factorization.

28691087 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15897.

The product of its (nonzero) digits is 48384, while the sum is 41.

The square root of 28691087 is about 5356.4061645846. The cubic root of 28691087 is about 306.1368910636.

The spelling of 28691087 in words is "twenty-eight million, six hundred ninety-one thousand, eighty-seven".