28001031 has 4 divisors (see below), whose sum is σ = 37334712. Its totient is φ = 18667352.

The previous prime is 28001009. The next prime is 28001047. The reversal of 28001031 is 13010082.

It is a happy number.

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 28001031 - 2¹⁴ = 27984647 is a prime.

It is a super-2 number, since 2×28001031² = 1568115474125922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28001031.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28001081) 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, 4666836 + ... + 4666841.

It is an arithmetic number, because the mean of its divisors is an integer number (9333678).

Almost surely, 2^28001031 is an apocalyptic number.

28001031 is a deficient number, since it is larger than the sum of its proper divisors (9333681).

28001031 is an equidigital number, since it uses as much as digits as its factorization.

28001031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9333680.

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 28001031 is about 5291.6000415753. The cubic root of 28001031 is about 303.6626241933.

The spelling of 28001031 in words is "twenty-eight million, one thousand, thirty-one".