28273531 has 24 divisors (see below), whose sum is σ = 34046784. Its totient is φ = 23268960.

The previous prime is 28273529. The next prime is 28273541. The reversal of 28273531 is 13537282.

It is not a de Polignac number, because 28273531 - 2¹ = 28273529 is a prime.

It is a super-2 number, since 2×28273531² = 1598785110415922, 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 = 28273493 and 28273502.

It is not an unprimeable number, because it can be changed into a prime (28273541) 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, 124440 + ... + 124666.

It is an arithmetic number, because the mean of its divisors is an integer number (1418616).

Almost surely, 2^28273531 is an apocalyptic number.

28273531 is a deficient number, since it is larger than the sum of its proper divisors (5773253).

28273531 is a wasteful number, since it uses less digits than its factorization.

28273531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331 (or 318 counting only the distinct ones).

The product of its digits is 10080, while the sum is 31.

The square root of 28273531 is about 5317.2860558747. The cubic root of 28273531 is about 304.6445056371.

The spelling of 28273531 in words is "twenty-eight million, two hundred seventy-three thousand, five hundred thirty-one".