28249140 has 24 divisors (see below), whose sum is σ = 79097760. Its totient is φ = 7533088.

The previous prime is 28249139. The next prime is 28249147. The reversal of 28249140 is 4194282.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 28249098 and 28249107.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28249147) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 235350 + ... + 235469.

It is an arithmetic number, because the mean of its divisors is an integer number (3295740).

Almost surely, 2^28249140 is an apocalyptic number.

28249140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28249140 is an abundant number, since it is smaller than the sum of its proper divisors (50848620).

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

28249140 is a wasteful number, since it uses less digits than its factorization.

28249140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 470831 (or 470829 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 28249140 is about 5314.9920037569. The cubic root of 28249140 is about 304.5568768946.

It can be divided in two parts, 282 and 49140, that multiplied together give a triangular number (13857480 = T₅₂₆₄).

The spelling of 28249140 in words is "twenty-eight million, two hundred forty-nine thousand, one hundred forty".