549128639 has 4 divisors (see below), whose sum is σ = 550861224. Its totient is φ = 547396056.

The previous prime is 549128627. The next prime is 549128647. The reversal of 549128639 is 936821945.

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

It is a cyclic number.

It is not a de Polignac number, because 549128639 - 2⁸ = 549128383 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 549128593 and 549128602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (549128939) 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, 865817 + ... + 866450.

It is an arithmetic number, because the mean of its divisors is an integer number (137715306).

Almost surely, 2^549128639 is an apocalyptic number.

549128639 is a deficient number, since it is larger than the sum of its proper divisors (1732585).

549128639 is a wasteful number, since it uses less digits than its factorization.

549128639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1732584.

The product of its digits is 466560, while the sum is 47.

The square root of 549128639 is about 23433.4939563011. The cubic root of 549128639 is about 818.8883603245. Note that the first 3 decimals are identical.

The spelling of 549128639 in words is "five hundred forty-nine million, one hundred twenty-eight thousand, six hundred thirty-nine".