28018331521 has 8 divisors (see below), whose sum is σ = 29238618240. Its totient is φ = 26798219712.

The previous prime is 28018331503. The next prime is 28018331543. The reversal of 28018331521 is 12513381082.

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 28018331521 - 2⁹ = 28018331009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28018331021) 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, 365020 + ... + 435058.

It is an arithmetic number, because the mean of its divisors is an integer number (3654827280).

Almost surely, 2^28018331521 is an apocalyptic number.

It is an amenable number.

28018331521 is a deficient number, since it is larger than the sum of its proper divisors (1220286719).

28018331521 is a wasteful number, since it uses less digits than its factorization.

28018331521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87455.

The product of its (nonzero) digits is 11520, while the sum is 34.

The spelling of 28018331521 in words is "twenty-eight billion, eighteen million, three hundred thirty-one thousand, five hundred twenty-one".