128856493 has 2 divisors, whose sum is σ = 128856494. Its totient is φ = 128856492.

The previous prime is 128856487. The next prime is 128856517. The reversal of 128856493 is 394658821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 87665769 + 41190724 = 9363^2 + 6418^2 .

It is a cyclic number.

It is not a de Polignac number, because 128856493 - 2⁹ = 128855981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128856443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64428246 + 64428247.

It is an arithmetic number, because the mean of its divisors is an integer number (64428247).

Almost surely, 2^128856493 is an apocalyptic number.

It is an amenable number.

128856493 is a deficient number, since it is larger than the sum of its proper divisors (1).

128856493 is an equidigital number, since it uses as much as digits as its factorization.

128856493 is an evil number, because the sum of its binary digits is even.

The product of its digits is 414720, while the sum is 46.

The square root of 128856493 is about 11351.4973902124. The cubic root of 128856493 is about 505.0899986644.

The spelling of 128856493 in words is "one hundred twenty-eight million, eight hundred fifty-six thousand, four hundred ninety-three".