28161520 has 40 divisors (see below), whose sum is σ = 69330384. Its totient is φ = 10601472.

The previous prime is 28161509. The next prime is 28161541. The reversal of 28161520 is 2516182.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8994 + ... + 11713.

Almost surely, 2^28161520 is an apocalyptic number.

28161520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28161520 is an abundant number, since it is smaller than the sum of its proper divisors (41168864).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28161520 is a wasteful number, since it uses less digits than its factorization.

28161520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20737 (or 20731 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 28161520 is about 5306.7428805247. The cubic root of 28161520 is about 304.2416707091.

The spelling of 28161520 in words is "twenty-eight million, one hundred sixty-one thousand, five hundred twenty".