28161831 has 8 divisors (see below), whose sum is σ = 37597824. Its totient is φ = 18750200.

The previous prime is 28161827. The next prime is 28161839. The reversal of 28161831 is 13816182.

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 28161831 - 2² = 28161827 is a prime.

It is a super-2 number, since 2×28161831² = 1586177450545122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28161839) 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, 3195 + ... + 8156.

It is an arithmetic number, because the mean of its divisors is an integer number (4699728).

Almost surely, 2^28161831 is an apocalyptic number.

28161831 is a deficient number, since it is larger than the sum of its proper divisors (9435993).

28161831 is a wasteful number, since it uses less digits than its factorization.

28161831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12181.

The product of its digits is 2304, while the sum is 30.

The square root of 28161831 is about 5306.7721827868. The cubic root of 28161831 is about 304.2427906630.

The spelling of 28161831 in words is "twenty-eight million, one hundred sixty-one thousand, eight hundred thirty-one".