28535531 has 8 divisors (see below), whose sum is σ = 30142464. Its totient is φ = 26971560.

The previous prime is 28535513. The next prime is 28535543. The reversal of 28535531 is 13553582.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28535531 - 2¹⁰ = 28534507 is a prime.

It is a super-2 number, since 2×28535531² = 1628553058903922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28535581) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9371 + ... + 12036.

It is an arithmetic number, because the mean of its divisors is an integer number (3767808).

Almost surely, 2^28535531 is an apocalyptic number.

28535531 is a deficient number, since it is larger than the sum of its proper divisors (1606933).

28535531 is a wasteful number, since it uses less digits than its factorization.

28535531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21481.

The product of its digits is 18000, while the sum is 32.

The square root of 28535531 is about 5341.8658725206. The cubic root of 28535531 is about 305.5826219011.

The spelling of 28535531 in words is "twenty-eight million, five hundred thirty-five thousand, five hundred thirty-one".