28217761 has 24 divisors (see below), whose sum is σ = 34204896. Its totient is φ = 23063040.

The previous prime is 28217741. The next prime is 28217779. The reversal of 28217761 is 16771282.

It is a happy number.

It is not a de Polignac number, because 28217761 - 2⁵ = 28217729 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28217701) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 79761 + ... + 80113.

It is an arithmetic number, because the mean of its divisors is an integer number (1425204).

Almost surely, 2^28217761 is an apocalyptic number.

It is an amenable number.

28217761 is a deficient number, since it is larger than the sum of its proper divisors (5987135).

28217761 is a wasteful number, since it uses less digits than its factorization.

28217761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433 (or 420 counting only the distinct ones).

The product of its digits is 9408, while the sum is 34.

The square root of 28217761 is about 5312.0392506080. The cubic root of 28217761 is about 304.4440683757. Note that the first 3 decimals are identical.

The spelling of 28217761 in words is "twenty-eight million, two hundred seventeen thousand, seven hundred sixty-one".