28156224 has 28 divisors (see below), whose sum is σ = 74497184. Its totient is φ = 9385344.

The previous prime is 28156213. The next prime is 28156231. The reversal of 28156224 is 42265182.

It is a junction number, because it is equal to n+sod(n) for n = 28156191 and 28156200.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 73132 + ... + 73515.

Almost surely, 2^28156224 is an apocalyptic number.

28156224 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

28156224 is an abundant number, since it is smaller than the sum of its proper divisors (46340960).

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

28156224 is a wasteful number, since it uses less digits than its factorization.

28156224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146662 (or 146652 counting only the distinct ones).

The product of its digits is 7680, while the sum is 30.

The square root of 28156224 is about 5306.2438692544. The cubic root of 28156224 is about 304.2225978170. Note that the first 3 decimals are identical.

The spelling of 28156224 in words is "twenty-eight million, one hundred fifty-six thousand, two hundred twenty-four".