128720433 has 8 divisors (see below), whose sum is σ = 173556000. Its totient is φ = 84849248.

The previous prime is 128720429. The next prime is 128720437. The reversal of 128720433 is 334027821.

It is an interprime number because it is at equal distance from previous prime (128720429) and next prime (128720437).

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 128720433 - 2² = 128720429 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 128720433.

It is not an unprimeable number, because it can be changed into a prime (128720437) 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, 240783 + ... + 241316.

It is an arithmetic number, because the mean of its divisors is an integer number (21694500).

Almost surely, 2^128720433 is an apocalyptic number.

It is an amenable number.

128720433 is a deficient number, since it is larger than the sum of its proper divisors (44835567).

128720433 is an equidigital number, since it uses as much as digits as its factorization.

128720433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 482191.

The product of its (nonzero) digits is 8064, while the sum is 30.

The square root of 128720433 is about 11345.5027654133. The cubic root of 128720433 is about 504.9121606526.

The spelling of 128720433 in words is "one hundred twenty-eight million, seven hundred twenty thousand, four hundred thirty-three".