28403820 has 36 divisors (see below), whose sum is σ = 86158800. Its totient is φ = 7574304.

The previous prime is 28403807. The next prime is 28403833. The reversal of 28403820 is 2830482.

28403820 is a `hidden beast` number, since 284 + 0 + 382 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (28403807) and next prime (28403833).

It is a tau number, because it is divible by the number of its divisors (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 78720 + ... + 79079.

It is an arithmetic number, because the mean of its divisors is an integer number (2393300).

Almost surely, 2^28403820 is an apocalyptic number.

28403820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28403820 is an abundant number, since it is smaller than the sum of its proper divisors (57754980).

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

28403820 is a wasteful number, since it uses less digits than its factorization.

28403820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157814 (or 157809 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

The square root of 28403820 is about 5329.5234308520. The cubic root of 28403820 is about 305.1117390460. Note that the first 3 decimals are identical.

The spelling of 28403820 in words is "twenty-eight million, four hundred three thousand, eight hundred twenty".