28531641 has 4 divisors (see below), whose sum is σ = 38042192. Its totient is φ = 19021092.

The previous prime is 28531639. The next prime is 28531651. The reversal of 28531641 is 14613582.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 28531641 - 2¹ = 28531639 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28531599 and 28531608.

It is not an unprimeable number, because it can be changed into a prime (28531651) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4755271 + ... + 4755276.

It is an arithmetic number, because the mean of its divisors is an integer number (9510548).

Almost surely, 2^28531641 is an apocalyptic number.

It is an amenable number.

28531641 is a deficient number, since it is larger than the sum of its proper divisors (9510551).

28531641 is an equidigital number, since it uses as much as digits as its factorization.

28531641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9510550.

The product of its digits is 5760, while the sum is 30.

The square root of 28531641 is about 5341.5017551247. The cubic root of 28531641 is about 305.5687354658.

The spelling of 28531641 in words is "twenty-eight million, five hundred thirty-one thousand, six hundred forty-one".