28424787421 has 2 divisors, whose sum is σ = 28424787422. Its totient is φ = 28424787420.

The previous prime is 28424787409. The next prime is 28424787431. The reversal of 28424787421 is 12478742482.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24153511396 + 4271276025 = 155414^2 + 65355^2 .

It is a cyclic number.

It is not a de Polignac number, because 28424787421 - 2¹¹ = 28424785373 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28424787431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14212393710 + 14212393711.

It is an arithmetic number, because the mean of its divisors is an integer number (14212393711).

Almost surely, 2^28424787421 is an apocalyptic number.

It is an amenable number.

28424787421 is a deficient number, since it is larger than the sum of its proper divisors (1).

28424787421 is an equidigital number, since it uses as much as digits as its factorization.

28424787421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1605632, while the sum is 49.

The spelling of 28424787421 in words is "twenty-eight billion, four hundred twenty-four million, seven hundred eighty-seven thousand, four hundred twenty-one".