28713231 has 8 divisors (see below), whose sum is σ = 42538160. Its totient is φ = 19142136.

The previous prime is 28713229. The next prime is 28713233. The reversal of 28713231 is 13231782.

It is an interprime number because it is at equal distance from previous prime (28713229) and next prime (28713233).

It is not a de Polignac number, because 28713231 - 2¹ = 28713229 is a prime.

It is a super-2 number, since 2×28713231² = 1648899268918722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 1063453 = 28713231 / (2 + 8 + 7 + 1 + 3 + 2 + 3 + 1).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28713195 and 28713204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28713233) 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, 531700 + ... + 531753.

It is an arithmetic number, because the mean of its divisors is an integer number (5317270).

Almost surely, 2^28713231 is an apocalyptic number.

28713231 is a deficient number, since it is larger than the sum of its proper divisors (13824929).

28713231 is a wasteful number, since it uses less digits than its factorization.

28713231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1063462 (or 1063456 counting only the distinct ones).

The product of its digits is 2016, while the sum is 27.

The square root of 28713231 is about 5358.4728234825. The cubic root of 28713231 is about 306.2156304064.

The spelling of 28713231 in words is "twenty-eight million, seven hundred thirteen thousand, two hundred thirty-one".