28331919 has 24 divisors (see below), whose sum is σ = 51023232. Its totient is φ = 14717520.

The previous prime is 28331893. The next prime is 28331939. The reversal of 28331919 is 91913382.

It is not a de Polignac number, because 28331919 - 2¹² = 28327823 is a prime.

It is a super-2 number, since 2×28331919² = 1605395268445122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28331939) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19749 + ... + 21134.

It is an arithmetic number, because the mean of its divisors is an integer number (2125968).

Almost surely, 2^28331919 is an apocalyptic number.

28331919 is a deficient number, since it is larger than the sum of its proper divisors (22691313).

28331919 is a wasteful number, since it uses less digits than its factorization.

28331919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40907 (or 40904 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

The square root of 28331919 is about 5322.7736190824. The cubic root of 28331919 is about 304.8540697576.

The spelling of 28331919 in words is "twenty-eight million, three hundred thirty-one thousand, nine hundred nineteen".