128724131 has 2 divisors, whose sum is σ = 128724132. Its totient is φ = 128724130.

The previous prime is 128724083. The next prime is 128724151. The reversal of 128724131 is 131427821.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128724131 is a prime.

It is a super-2 number, since 2×128724131² = 33139803803410322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 128724094 and 128724103.

It is not a weakly prime, because it can be changed into another prime (128724151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64362065 + 64362066.

It is an arithmetic number, because the mean of its divisors is an integer number (64362066).

Almost surely, 2^128724131 is an apocalyptic number.

128724131 is a deficient number, since it is larger than the sum of its proper divisors (1).

128724131 is an equidigital number, since it uses as much as digits as its factorization.

128724131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2688, while the sum is 29.

The square root of 128724131 is about 11345.6657363065. The cubic root of 128724131 is about 504.9169958013.

The spelling of 128724131 in words is "one hundred twenty-eight million, seven hundred twenty-four thousand, one hundred thirty-one".