28426639 has 4 divisors (see below), whose sum is σ = 28490400. Its totient is φ = 28362880.

The previous prime is 28426637. The next prime is 28426663. The reversal of 28426639 is 93662482.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93662482 = 2 ⋅46831241.

It is a cyclic number.

It is not a de Polignac number, because 28426639 - 2¹ = 28426637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28426631) 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 in 3 ways as a sum of consecutive naturals, for example, 31207 + ... + 32104.

It is an arithmetic number, because the mean of its divisors is an integer number (7122600).

Almost surely, 2^28426639 is an apocalyptic number.

28426639 is a deficient number, since it is larger than the sum of its proper divisors (63761).

28426639 is an equidigital number, since it uses as much as digits as its factorization.

28426639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63760.

The product of its digits is 124416, while the sum is 40.

The square root of 28426639 is about 5331.6638116070. The cubic root of 28426639 is about 305.1934238469.

The spelling of 28426639 in words is "twenty-eight million, four hundred twenty-six thousand, six hundred thirty-nine".