28609380 has 36 divisors (see below), whose sum is σ = 86782332. Its totient is φ = 7629120.

The previous prime is 28609369. The next prime is 28609381. The reversal of 28609380 is 8390682.

It can be written as a sum of positive squares in 2 ways, for example, as 19501056 + 9108324 = 4416^2 + 3018^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (28609381) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 79291 + ... + 79650.

Almost surely, 2^28609380 is an apocalyptic number.

28609380 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28609380 is an abundant number, since it is smaller than the sum of its proper divisors (58172952).

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

28609380 is a wasteful number, since it uses less digits than its factorization.

28609380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158956 (or 158951 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 28609380 is about 5348.7736912305. The cubic root of 28609380 is about 305.8460073563.

The spelling of 28609380 in words is "twenty-eight million, six hundred nine thousand, three hundred eighty".