128289731 has 8 divisors (see below), whose sum is σ = 129300624. Its totient is φ = 127283200.

The previous prime is 128289709. The next prime is 128289761. The reversal of 128289731 is 137982821.

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 128289731 - 2¹⁰ = 128288707 is a prime.

It is a super-2 number, since 2×128289731² = 32916510160104722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128289761) 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, 79331 + ... + 80931.

It is an arithmetic number, because the mean of its divisors is an integer number (16162578).

Almost surely, 2^128289731 is an apocalyptic number.

128289731 is a deficient number, since it is larger than the sum of its proper divisors (1010893).

128289731 is a wasteful number, since it uses less digits than its factorization.

128289731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2181.

The product of its digits is 48384, while the sum is 41.

The square root of 128289731 is about 11326.5056835725. The cubic root of 128289731 is about 504.3483815281.

The spelling of 128289731 in words is "one hundred twenty-eight million, two hundred eighty-nine thousand, seven hundred thirty-one".