156728389 has 8 divisors (see below), whose sum is σ = 166325400. Its totient is φ = 147173376.

The previous prime is 156728387. The next prime is 156728393. The reversal of 156728389 is 983827651.

It can be written as a sum of positive squares in 4 ways, for example, as 63760225 + 92968164 = 7985^2 + 9642^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 156728389 - 2¹ = 156728387 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 (156728381) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2634 + ... + 17899.

It is an arithmetic number, because the mean of its divisors is an integer number (20790675).

Almost surely, 2^156728389 is an apocalyptic number.

It is an amenable number.

156728389 is a deficient number, since it is larger than the sum of its proper divisors (9597011).

156728389 is a wasteful number, since it uses less digits than its factorization.

156728389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20999.

The product of its digits is 725760, while the sum is 49.

The square root of 156728389 is about 12519.1209355929. The cubic root of 156728389 is about 539.1577966631.

The spelling of 156728389 in words is "one hundred fifty-six million, seven hundred twenty-eight thousand, three hundred eighty-nine".