28421639 has 2 divisors, whose sum is σ = 28421640. Its totient is φ = 28421638.

The previous prime is 28421633. The next prime is 28421681. The reversal of 28421639 is 93612482.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28421639 - 2⁴ = 28421623 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 28421599 and 28421608.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28421633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14210819 + 14210820.

It is an arithmetic number, because the mean of its divisors is an integer number (14210820).

Almost surely, 2^28421639 is an apocalyptic number.

28421639 is a deficient number, since it is larger than the sum of its proper divisors (1).

28421639 is an equidigital number, since it uses as much as digits as its factorization.

28421639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20736, while the sum is 35.

The square root of 28421639 is about 5331.1948942052. The cubic root of 28421639 is about 305.1755291696.

The spelling of 28421639 in words is "twenty-eight million, four hundred twenty-one thousand, six hundred thirty-nine".