28478457 has 18 divisors (see below), whose sum is σ = 47852298. Its totient is φ = 16273152.

The previous prime is 28478441. The next prime is 28478467. The reversal of 28478457 is 75487482.

It can be written as a sum of positive squares in only one way, i.e., 26255376 + 2223081 = 5124^2 + 1491^2 .

It is not a de Polignac number, because 28478457 - 2⁴ = 28478441 is a prime.

It is a super-2 number, since 2×28478457² = 1622045026201698, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28478467) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 31848 + ... + 32729.

It is an arithmetic number, because the mean of its divisors is an integer number (2658461).

Almost surely, 2^28478457 is an apocalyptic number.

It is an amenable number.

28478457 is a deficient number, since it is larger than the sum of its proper divisors (19373841).

28478457 is a wasteful number, since it uses less digits than its factorization.

28478457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64597 (or 64587 counting only the distinct ones).

The product of its digits is 501760, while the sum is 45.

The square root of 28478457 is about 5336.5210577679. The cubic root of 28478457 is about 305.3787536860.

The spelling of 28478457 in words is "twenty-eight million, four hundred seventy-eight thousand, four hundred fifty-seven".