128381497 has 2 divisors, whose sum is σ = 128381498. Its totient is φ = 128381496.

The previous prime is 128381471. The next prime is 128381503. The reversal of 128381497 is 794183821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 125350416 + 3031081 = 11196^2 + 1741^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128381497 is a prime.

It is a super-2 number, since 2×128381497² = 32963617543922018, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (128381597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64190748 + 64190749.

It is an arithmetic number, because the mean of its divisors is an integer number (64190749).

Almost surely, 2^128381497 is an apocalyptic number.

It is an amenable number.

128381497 is a deficient number, since it is larger than the sum of its proper divisors (1).

128381497 is an equidigital number, since it uses as much as digits as its factorization.

128381497 is an evil number, because the sum of its binary digits is even.

The product of its digits is 96768, while the sum is 43.

The square root of 128381497 is about 11330.5558998665. Note that the first 3 decimals coincide. The cubic root of 128381497 is about 504.4686067984.

The spelling of 128381497 in words is "one hundred twenty-eight million, three hundred eighty-one thousand, four hundred ninety-seven".