128724437 has 2 divisors, whose sum is σ = 128724438. Its totient is φ = 128724436.

The previous prime is 128724433. The next prime is 128724469. The reversal of 128724437 is 734427821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 125305636 + 3418801 = 11194^2 + 1849^2 .

It is an emirp because it is prime and its reverse (734427821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 128724437 - 2² = 128724433 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 128724437.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128724433) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64362218 + 64362219.

It is an arithmetic number, because the mean of its divisors is an integer number (64362219).

Almost surely, 2^128724437 is an apocalyptic number.

It is an amenable number.

128724437 is a deficient number, since it is larger than the sum of its proper divisors (1).

128724437 is an equidigital number, since it uses as much as digits as its factorization.

128724437 is an evil number, because the sum of its binary digits is even.

The product of its digits is 75264, while the sum is 38.

The square root of 128724437 is about 11345.6792216244. The cubic root of 128724437 is about 504.9173958933.

The spelling of 128724437 in words is "one hundred twenty-eight million, seven hundred twenty-four thousand, four hundred thirty-seven".