28645501 has 4 divisors (see below), whose sum is σ = 28764604. Its totient is φ = 28526400.

The previous prime is 28645499. The next prime is 28645517. The reversal of 28645501 is 10554682.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 10554682 = 2 ⋅5277341.

It can be written as a sum of positive squares in 2 ways, for example, as 12243001 + 16402500 = 3499^2 + 4050^2 .

It is a cyclic number.

It is not a de Polignac number, because 28645501 - 2¹ = 28645499 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28645531) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 59190 + ... + 59671.

It is an arithmetic number, because the mean of its divisors is an integer number (7191151).

Almost surely, 2^28645501 is an apocalyptic number.

It is an amenable number.

28645501 is a deficient number, since it is larger than the sum of its proper divisors (119103).

28645501 is a wasteful number, since it uses less digits than its factorization.

28645501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119102.

The product of its (nonzero) digits is 9600, while the sum is 31.

The square root of 28645501 is about 5352.1491944825. The cubic root of 28645501 is about 305.9746693259.

The spelling of 28645501 in words is "twenty-eight million, six hundred forty-five thousand, five hundred one".