28971553 has 16 divisors (see below), whose sum is σ = 33218640. Its totient is φ = 25030656.

The previous prime is 28971541. The next prime is 28971601. The reversal of 28971553 is 35517982.

It can be written as a sum of positive squares in 8 ways, for example, as 2634129 + 26337424 = 1623^2 + 5132^2 .

It is a cyclic number.

It is not a de Polignac number, because 28971553 - 2⁵ = 28971521 is a prime.

Its product of digits (75600) is a multiple of the sum of its prime divisors (756).

It is not an unprimeable number, because it can be changed into a prime (28971533) 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, 74283 + ... + 74671.

It is an arithmetic number, because the mean of its divisors is an integer number (2076165).

Almost surely, 2^28971553 is an apocalyptic number.

It is an amenable number.

28971553 is a deficient number, since it is larger than the sum of its proper divisors (4247087).

28971553 is a wasteful number, since it uses less digits than its factorization.

28971553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 756.

The product of its digits is 75600, while the sum is 40.

The square root of 28971553 is about 5382.5229214561. The cubic root of 28971553 is about 307.1311920059.

The spelling of 28971553 in words is "twenty-eight million, nine hundred seventy-one thousand, five hundred fifty-three".