28725642 has 60 divisors (see below), whose sum is σ = 69090450. Its totient is φ = 8624880.

The previous prime is 28725611. The next prime is 28725691. The reversal of 28725642 is 24652782.

28725642 is a `hidden beast` number, since 2 + 8 + 7 + 2 + 5 + 642 = 666.

It can be written as a sum of positive squares in only one way, i.e., 22268961 + 6456681 = 4719^2 + 2541^2 .

It is a junction number, because it is equal to n+sod(n) for n = 28725597 and 28725606.

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 263484 + ... + 263592.

Almost surely, 2^28725642 is an apocalyptic number.

28725642 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 28725642, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34545225).

28725642 is an abundant number, since it is smaller than the sum of its proper divisors (40364808).

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

28725642 is a wasteful number, since it uses less digits than its factorization.

28725642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161 (or 125 counting only the distinct ones).

The product of its digits is 53760, while the sum is 36.

The square root of 28725642 is about 5359.6307708647. The cubic root of 28725642 is about 306.2597435745.

The spelling of 28725642 in words is "twenty-eight million, seven hundred twenty-five thousand, six hundred forty-two".