28515501 has 18 divisors (see below), whose sum is σ = 47914542. Its totient is φ = 16294320.

The previous prime is 28515491. The next prime is 28515559. The reversal of 28515501 is 10551582.

It can be written as a sum of positive squares in only one way, i.e., 15920100 + 12595401 = 3990^2 + 3549^2 .

It is not a de Polignac number, because 28515501 - 2⁷ = 28515373 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28515601) 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, 31890 + ... + 32771.

It is an arithmetic number, because the mean of its divisors is an integer number (2661919).

Almost surely, 2^28515501 is an apocalyptic number.

28515501 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

28515501 is a deficient number, since it is larger than the sum of its proper divisors (19399041).

28515501 is a wasteful number, since it uses less digits than its factorization.

28515501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64681 (or 64671 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 27.

The square root of 28515501 is about 5339.9907303290. The cubic root of 28515501 is about 305.5111057667.

The spelling of 28515501 in words is "twenty-eight million, five hundred fifteen thousand, five hundred one".