28340031 has 4 divisors (see below), whose sum is σ = 37786712. Its totient is φ = 18893352.

The previous prime is 28340027. The next prime is 28340041. The reversal of 28340031 is 13004382.

It is a happy number.

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

It is not a de Polignac number, because 28340031 - 2² = 28340027 is a prime.

It is a super-2 number, since 2×28340031² = 1606314714161922, 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 (28340021) 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, 4723336 + ... + 4723341.

It is an arithmetic number, because the mean of its divisors is an integer number (9446678).

Almost surely, 2^28340031 is an apocalyptic number.

28340031 is a deficient number, since it is larger than the sum of its proper divisors (9446681).

28340031 is an equidigital number, since it uses as much as digits as its factorization.

28340031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9446680.

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 28340031 is about 5323.5355732821. The cubic root of 28340031 is about 304.8831622714.

The spelling of 28340031 in words is "twenty-eight million, three hundred forty thousand, thirty-one".