28142731 has 8 divisors (see below), whose sum is σ = 30379680. Its totient is φ = 25990272.

The previous prime is 28142729. The next prime is 28142749. The reversal of 28142731 is 13724182.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28142731 - 2¹ = 28142729 is a prime.

It is a super-2 number, since 2×28142731² = 1584026616276722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28142731.

It is not an unprimeable number, because it can be changed into a prime (28142711) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20430 + ... + 21763.

It is an arithmetic number, because the mean of its divisors is an integer number (3797460).

Almost surely, 2^28142731 is an apocalyptic number.

28142731 is a deficient number, since it is larger than the sum of its proper divisors (2236949).

28142731 is a wasteful number, since it uses less digits than its factorization.

28142731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42245.

The product of its digits is 2688, while the sum is 28.

The square root of 28142731 is about 5304.9722902198. The cubic root of 28142731 is about 304.1739936268.

The spelling of 28142731 in words is "twenty-eight million, one hundred forty-two thousand, seven hundred thirty-one".