28343531 has 4 divisors (see below), whose sum is σ = 28396464. Its totient is φ = 28290600.

The previous prime is 28343507. The next prime is 28343537. The reversal of 28343531 is 13534382.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13534382 = 2 ⋅6767191.

It is a cyclic number.

It is not a de Polignac number, because 28343531 - 2¹⁸ = 28081387 is a prime.

It is a super-2 number, since 2×28343531² = 1606711499095922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28343494 and 28343503.

It is not an unprimeable number, because it can be changed into a prime (28343537) 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, 25655 + ... + 26736.

It is an arithmetic number, because the mean of its divisors is an integer number (7099116).

Almost surely, 2^28343531 is an apocalyptic number.

28343531 is a deficient number, since it is larger than the sum of its proper divisors (52933).

28343531 is an equidigital number, since it uses as much as digits as its factorization.

28343531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52932.

The product of its digits is 8640, while the sum is 29.

The square root of 28343531 is about 5323.8642920345. The cubic root of 28343531 is about 304.8957128004.

The spelling of 28343531 in words is "twenty-eight million, three hundred forty-three thousand, five hundred thirty-one".