28903391 has 12 divisors (see below), whose sum is σ = 32376456. Its totient is φ = 25774320.

The previous prime is 28903367. The next prime is 28903393. The reversal of 28903391 is 19330982.

It is not a de Polignac number, because 28903391 - 2¹⁴ = 28887007 is a prime.

It is a super-2 number, since 2×28903391² = 1670812022597762, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28903393) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4160 + ... + 8666.

It is an arithmetic number, because the mean of its divisors is an integer number (2698038).

Almost surely, 2^28903391 is an apocalyptic number.

28903391 is a deficient number, since it is larger than the sum of its proper divisors (3473065).

28903391 is a wasteful number, since it uses less digits than its factorization.

28903391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4582 (or 4571 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 35.

The square root of 28903391 is about 5376.1874037277. The cubic root of 28903391 is about 306.8901381277.

The spelling of 28903391 in words is "twenty-eight million, nine hundred three thousand, three hundred ninety-one".