428228639 has 4 divisors (see below), whose sum is σ = 439802424. Its totient is φ = 416654856.

The previous prime is 428228629. The next prime is 428228653. The reversal of 428228639 is 936822824.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-428228639 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 428228639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (428228629) 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, 5786837 + ... + 5786910.

It is an arithmetic number, because the mean of its divisors is an integer number (109950606).

Almost surely, 2^428228639 is an apocalyptic number.

428228639 is a deficient number, since it is larger than the sum of its proper divisors (11573785).

428228639 is a wasteful number, since it uses less digits than its factorization.

428228639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11573784.

The product of its digits is 331776, while the sum is 44.

The square root of 428228639 is about 20693.6859693966. The cubic root of 428228639 is about 753.7463744856.

The spelling of 428228639 in words is "four hundred twenty-eight million, two hundred twenty-eight thousand, six hundred thirty-nine".