28153640 has 32 divisors (see below), whose sum is σ = 63511560. Its totient is φ = 11232000.

The previous prime is 28153639. The next prime is 28153661. The reversal of 28153640 is 4635182.

It can be written as a sum of positive squares in 4 ways, for example, as 11195716 + 16957924 = 3346^2 + 4118^2 .

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 7 ways as a sum of consecutive naturals, for example, 20990 + ... + 22290.

Almost surely, 2^28153640 is an apocalyptic number.

28153640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28153640 is an abundant number, since it is smaller than the sum of its proper divisors (35357920).

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

28153640 is a wasteful number, since it uses less digits than its factorization.

28153640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1853 (or 1849 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 29.

The square root of 28153640 is about 5306.0003769318. Note that the first 3 decimals coincide. The cubic root of 28153640 is about 304.2132909909.

The spelling of 28153640 in words is "twenty-eight million, one hundred fifty-three thousand, six hundred forty".