28742831 has 4 divisors (see below), whose sum is σ = 30953832. Its totient is φ = 26531832.

The previous prime is 28742827. The next prime is 28742843. The reversal of 28742831 is 13824782.

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

It is a cyclic number.

It is not a de Polignac number, because 28742831 - 2² = 28742827 is a prime.

It is a super-2 number, since 2×28742831² = 1652300667789122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28742791 and 28742800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28742851) 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, 1105481 + ... + 1105506.

It is an arithmetic number, because the mean of its divisors is an integer number (7738458).

Almost surely, 2^28742831 is an apocalyptic number.

28742831 is a deficient number, since it is larger than the sum of its proper divisors (2211001).

28742831 is a wasteful number, since it uses less digits than its factorization.

28742831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2211000.

The product of its digits is 21504, while the sum is 35.

The square root of 28742831 is about 5361.2340930051. The cubic root of 28742831 is about 306.3208184967.

The spelling of 28742831 in words is "twenty-eight million, seven hundred forty-two thousand, eight hundred thirty-one".