28718718 has 32 divisors (see below), whose sum is σ = 65940480. Its totient is φ = 8168160.

The previous prime is 28718717. The next prime is 28718731. The reversal of 28718718 is 81781782.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 28718718.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28718713) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8608 + ... + 11468.

It is an arithmetic number, because the mean of its divisors is an integer number (2060640).

Almost surely, 2^28718718 is an apocalyptic number.

28718718 is an abundant number, since it is smaller than the sum of its proper divisors (37221762).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28718718 is a wasteful number, since it uses less digits than its factorization.

28718718 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3112.

The product of its digits is 50176, while the sum is 42.

The square root of 28718718 is about 5358.9847919172. The cubic root of 28718718 is about 306.2351347498.

The spelling of 28718718 in words is "twenty-eight million, seven hundred eighteen thousand, seven hundred eighteen".