28161290 has 24 divisors (see below), whose sum is σ = 51627780. Its totient is φ = 11059904.

The previous prime is 28161277. The next prime is 28161313. The reversal of 28161290 is 9216182.

It can be written as a sum of positive squares in 2 ways, for example, as 27573001 + 588289 = 5251^2 + 767^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 34406 + ... + 35214.

Almost surely, 2^28161290 is an apocalyptic number.

28161290 is a deficient number, since it is larger than the sum of its proper divisors (23466490).

28161290 is an equidigital number, since it uses as much as digits as its factorization.

28161290 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 934 (or 875 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 28161290 is about 5306.7212099375. The cubic root of 28161290 is about 304.2408424421.

The spelling of 28161290 in words is "twenty-eight million, one hundred sixty-one thousand, two hundred ninety".