28121535 has 48 divisors (see below), whose sum is σ = 53542944. Its totient is φ = 13568256.

The previous prime is 28121521. The next prime is 28121581. The reversal of 28121535 is 53512182.

It is a happy number.

28121535 is a `hidden beast` number, since 2 + 8 + 121 + 535 = 666.

It is not a de Polignac number, because 28121535 - 2¹⁰ = 28120511 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28121499 and 28121508.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 30552 + ... + 31458.

It is an arithmetic number, because the mean of its divisors is an integer number (1115478).

Almost surely, 2^28121535 is an apocalyptic number.

28121535 is a deficient number, since it is larger than the sum of its proper divisors (25421409).

28121535 is a wasteful number, since it uses less digits than its factorization.

28121535 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 984 (or 981 counting only the distinct ones).

The product of its digits is 2400, while the sum is 27.

The square root of 28121535 is about 5302.9741655037. The cubic root of 28121535 is about 304.0976104777.

The spelling of 28121535 in words is "twenty-eight million, one hundred twenty-one thousand, five hundred thirty-five".