28135431 has 20 divisors (see below), whose sum is σ = 42180600. Its totient is φ = 18689616.

The previous prime is 28135427. The next prime is 28135433. The reversal of 28135431 is 13453182.

It is a happy number.

28135431 is a `hidden beast` number, since 281 + 354 + 31 = 666.

It is not a de Polignac number, because 28135431 - 2² = 28135427 is a prime.

It is a super-2 number, since 2×28135431² = 1583204955111522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 28135395 and 28135404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28135433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 33525 + ... + 34353.

It is an arithmetic number, because the mean of its divisors is an integer number (2109030).

Almost surely, 2^28135431 is an apocalyptic number.

28135431 is a deficient number, since it is larger than the sum of its proper divisors (14045169).

28135431 is an equidigital number, since it uses as much as digits as its factorization.

28135431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1260 (or 1251 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 28135431 is about 5304.2842118423. The cubic root of 28135431 is about 304.1476912497.

The spelling of 28135431 in words is "twenty-eight million, one hundred thirty-five thousand, four hundred thirty-one".