28978660 has 24 divisors (see below), whose sum is σ = 61855416. Its totient is φ = 11400960.

The previous prime is 28978657. The next prime is 28978661. The reversal of 28978660 is 6687982.

It can be written as a sum of positive squares in 4 ways, for example, as 484416 + 28494244 = 696^2 + 5338^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 28978660.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28978661) 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, 10657 + ... + 13096.

It is an arithmetic number, because the mean of its divisors is an integer number (2577309).

Almost surely, 2^28978660 is an apocalyptic number.

28978660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28978660 is an abundant number, since it is smaller than the sum of its proper divisors (32876756).

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

28978660 is a wasteful number, since it uses less digits than its factorization.

28978660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23823 (or 23821 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 46.

The square root of 28978660 is about 5383.1830732384. The cubic root of 28978660 is about 307.1563040290.

The spelling of 28978660 in words is "twenty-eight million, nine hundred seventy-eight thousand, six hundred sixty".