28781536 has 24 divisors (see below), whose sum is σ = 64758960. Its totient is φ = 12334848.

The previous prime is 28781509. The next prime is 28781537. The reversal of 28781536 is 63518782.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28781537) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64021 + ... + 64468.

It is an arithmetic number, because the mean of its divisors is an integer number (2698290).

Almost surely, 2^28781536 is an apocalyptic number.

It is an amenable number.

28781536 is an abundant number, since it is smaller than the sum of its proper divisors (35977424).

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

28781536 is a wasteful number, since it uses less digits than its factorization.

28781536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128506 (or 128498 counting only the distinct ones).

The product of its digits is 80640, while the sum is 40.

The square root of 28781536 is about 5364.8425885575. The cubic root of 28781536 is about 306.4582536882.

The spelling of 28781536 in words is "twenty-eight million, seven hundred eighty-one thousand, five hundred thirty-six".