28907219 has 4 divisors (see below), whose sum is σ = 31535160. Its totient is φ = 26279280.

The previous prime is 28907213. The next prime is 28907231. The reversal of 28907219 is 91270982.

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

It is a cyclic number.

It is not a de Polignac number, because 28907219 - 2⁸ = 28906963 is a prime.

It is a super-2 number, since 2×28907219² = 1671254620627922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28907213) 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, 1313954 + ... + 1313975.

It is an arithmetic number, because the mean of its divisors is an integer number (7883790).

Almost surely, 2^28907219 is an apocalyptic number.

28907219 is a deficient number, since it is larger than the sum of its proper divisors (2627941).

28907219 is a wasteful number, since it uses less digits than its factorization.

28907219 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2627940.

The product of its (nonzero) digits is 18144, while the sum is 38.

The square root of 28907219 is about 5376.5434063160. The cubic root of 28907219 is about 306.9036858298.

The spelling of 28907219 in words is "twenty-eight million, nine hundred seven thousand, two hundred nineteen".