28161387 has 6 divisors (see below), whose sum is σ = 40677572. Its totient is φ = 18774252.

The previous prime is 28161359. The next prime is 28161389. The reversal of 28161387 is 78316182.

It is not a de Polignac number, because 28161387 - 2⁶ = 28161323 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28161389) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1564513 + ... + 1564530.

Almost surely, 2^28161387 is an apocalyptic number.

28161387 is a deficient number, since it is larger than the sum of its proper divisors (12516185).

28161387 is a wasteful number, since it uses less digits than its factorization.

28161387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3129049 (or 3129046 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 28161387 is about 5306.7303492829. The cubic root of 28161387 is about 304.2411917553.

The spelling of 28161387 in words is "twenty-eight million, one hundred sixty-one thousand, three hundred eighty-seven".