28215745 has 8 divisors (see below), whose sum is σ = 34579584. Its totient is φ = 22092144.

The previous prime is 28215743. The next prime is 28215757. The reversal of 28215745 is 54751282.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28215745 - 2¹ = 28215743 is a prime.

It is a super-2 number, since 2×28215745² = 1592256531810050, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28215745.

It is not an unprimeable number, because it can be changed into a prime (28215743) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 59799 + ... + 60268.

It is an arithmetic number, because the mean of its divisors is an integer number (4322448).

Almost surely, 2^28215745 is an apocalyptic number.

It is an amenable number.

28215745 is a deficient number, since it is larger than the sum of its proper divisors (6363839).

28215745 is a wasteful number, since it uses less digits than its factorization.

28215745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120119.

The product of its digits is 22400, while the sum is 34.

The square root of 28215745 is about 5311.8494895846. The cubic root of 28215745 is about 304.4368179320.

The spelling of 28215745 in words is "twenty-eight million, two hundred fifteen thousand, seven hundred forty-five".