28272738 has 48 divisors (see below), whose sum is σ = 63213696. Its totient is φ = 8379840.

The previous prime is 28272737. The next prime is 28272781. The reversal of 28272738 is 83727282.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a junction number, because it is equal to n+sod(n) for n = 28272696 and 28272705.

It is not an unprimeable number, because it can be changed into a prime (28272731) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 65383 + ... + 65813.

It is an arithmetic number, because the mean of its divisors is an integer number (1316952).

Almost surely, 2^28272738 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28272738, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31606848).

28272738 is an abundant number, since it is smaller than the sum of its proper divisors (34940958).

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

28272738 is a wasteful number, since it uses less digits than its factorization.

28272738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 507 (or 478 counting only the distinct ones).

The product of its digits is 75264, while the sum is 39.

The square root of 28272738 is about 5317.2114872365. The cubic root of 28272738 is about 304.6416574449.

It can be divided in two parts, 2827 and 2738, that added together give a triangular number (5565 = T₁₀₅).

The spelling of 28272738 in words is "twenty-eight million, two hundred seventy-two thousand, seven hundred thirty-eight".