28751438 has 4 divisors (see below), whose sum is σ = 43127160. Its totient is φ = 14375718.

The previous prime is 28751431. The next prime is 28751447. The reversal of 28751438 is 83415782.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83415782 = 2 ⋅41707891.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28751431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7187858 + ... + 7187861.

It is an arithmetic number, because the mean of its divisors is an integer number (10781790).

Almost surely, 2^28751438 is an apocalyptic number.

28751438 is a deficient number, since it is larger than the sum of its proper divisors (14375722).

28751438 is a wasteful number, since it uses less digits than its factorization.

28751438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14375721.

The product of its digits is 53760, while the sum is 38.

The square root of 28751438 is about 5362.0367398965. The cubic root of 28751438 is about 306.3513912236.

It can be divided in two parts, 2875 and 1438, that multiplied together give a triangular number (4134250 = T₂₈₇₅).

The spelling of 28751438 in words is "twenty-eight million, seven hundred fifty-one thousand, four hundred thirty-eight".