28921563 has 16 divisors (see below), whose sum is σ = 46742400. Its totient is φ = 17528040.

The previous prime is 28921507. The next prime is 28921577. The reversal of 28921563 is 36512982.

28921563 is a `hidden beast` number, since 2 + 8 + 92 + 1 + 563 = 666.

It is not a de Polignac number, because 28921563 - 2⁸ = 28921307 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28925563) 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, 48393 + ... + 48986.

It is an arithmetic number, because the mean of its divisors is an integer number (2921400).

Almost surely, 2^28921563 is an apocalyptic number.

28921563 is a deficient number, since it is larger than the sum of its proper divisors (17820837).

28921563 is a wasteful number, since it uses less digits than its factorization.

28921563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97399 (or 97393 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 28921563 is about 5377.8771834247. The cubic root of 28921563 is about 306.9544401475.

The spelling of 28921563 in words is "twenty-eight million, nine hundred twenty-one thousand, five hundred sixty-three".