28861919 has 4 divisors (see below), whose sum is σ = 28981920. Its totient is φ = 28741920.

The previous prime is 28861897. The next prime is 28861933. The reversal of 28861919 is 91916882.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 91916882 = 2 ⋅45958441.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28861919 is a prime.

It is a super-3 number, since 3×28861919³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28861919.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28861949) 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, 59639 + ... + 60120.

It is an arithmetic number, because the mean of its divisors is an integer number (7245480).

Almost surely, 2^28861919 is an apocalyptic number.

28861919 is a deficient number, since it is larger than the sum of its proper divisors (120001).

28861919 is a wasteful number, since it uses less digits than its factorization.

28861919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120000.

The product of its digits is 62208, while the sum is 44.

The square root of 28861919 is about 5372.3290107736. The cubic root of 28861919 is about 306.7432875391.

The spelling of 28861919 in words is "twenty-eight million, eight hundred sixty-one thousand, nine hundred nineteen".