28506738 has 16 divisors (see below), whose sum is σ = 61399296. Its totient is φ = 8771280.

The previous prime is 28506677. The next prime is 28506743. The reversal of 28506738 is 83760582.

It is a super-2 number, since 2×28506738² = 1625268222801288, which contains 22 as substring.

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

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 28506696 and 28506705.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 182658 + ... + 182813.

It is an arithmetic number, because the mean of its divisors is an integer number (3837456).

Almost surely, 2^28506738 is an apocalyptic number.

28506738 is an abundant number, since it is smaller than the sum of its proper divisors (32892558).

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

28506738 is a wasteful number, since it uses less digits than its factorization.

28506738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 365489.

The product of its (nonzero) digits is 80640, while the sum is 39.

The square root of 28506738 is about 5339.1701602403. The cubic root of 28506738 is about 305.4798073733.

The spelling of 28506738 in words is "twenty-eight million, five hundred six thousand, seven hundred thirty-eight".