28532887421 has 2 divisors, whose sum is σ = 28532887422. Its totient is φ = 28532887420.

The previous prime is 28532887367. The next prime is 28532887447. The reversal of 28532887421 is 12478823582.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18475605625 + 10057281796 = 135925^2 + 100286^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28532887421 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28532887421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28532887121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14266443710 + 14266443711.

It is an arithmetic number, because the mean of its divisors is an integer number (14266443711).

Almost surely, 2^28532887421 is an apocalyptic number.

It is an amenable number.

28532887421 is a deficient number, since it is larger than the sum of its proper divisors (1).

28532887421 is an equidigital number, since it uses as much as digits as its factorization.

28532887421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1720320, while the sum is 50.

The spelling of 28532887421 in words is "twenty-eight billion, five hundred thirty-two million, eight hundred eighty-seven thousand, four hundred twenty-one".