28912387 has 8 divisors (see below), whose sum is σ = 33140736. Its totient is φ = 24708552.

The previous prime is 28912381. The next prime is 28912463. The reversal of 28912387 is 78321982.

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 28912387 - 2¹⁹ = 28388099 is a prime.

It is a super-2 number, since 2×28912387² = 1671852244075538, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28912381) 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, 3523 + ... + 8380.

It is an arithmetic number, because the mean of its divisors is an integer number (4142592).

Almost surely, 2^28912387 is an apocalyptic number.

28912387 is a deficient number, since it is larger than the sum of its proper divisors (4228349).

28912387 is a wasteful number, since it uses less digits than its factorization.

28912387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12257.

The product of its digits is 48384, while the sum is 40.

The square root of 28912387 is about 5377.0239910196. The cubic root of 28912387 is about 306.9219740382.

The spelling of 28912387 in words is "twenty-eight million, nine hundred twelve thousand, three hundred eighty-seven".