28929381 has 16 divisors (see below), whose sum is σ = 43727040. Its totient is φ = 16865280.

The previous prime is 28929379. The next prime is 28929391. The reversal of 28929381 is 18392982.

It is not a de Polignac number, because 28929381 - 2¹ = 28929379 is a prime.

It is a super-2 number, since 2×28929381² = 1673818170086322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28929391) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18780 + ... + 20261.

It is an arithmetic number, because the mean of its divisors is an integer number (2732940).

Almost surely, 2^28929381 is an apocalyptic number.

It is an amenable number.

28929381 is a deficient number, since it is larger than the sum of its proper divisors (14797659).

28929381 is a wasteful number, since it uses less digits than its factorization.

28929381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39076.

The product of its digits is 62208, while the sum is 42.

The square root of 28929381 is about 5378.6040010397. The cubic root of 28929381 is about 306.9820960250.

The spelling of 28929381 in words is "twenty-eight million, nine hundred twenty-nine thousand, three hundred eighty-one".