128215849 has 2 divisors, whose sum is σ = 128215850. Its totient is φ = 128215848.

The previous prime is 128215837. The next prime is 128215889. The reversal of 128215849 is 948512821.

It is an a-pointer prime, because the next prime (128215889) can be obtained adding 128215849 to its sum of digits (40).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 128029225 + 186624 = 11315^2 + 432^2 .

It is a cyclic number.

It is not a de Polignac number, because 128215849 - 2¹³ = 128207657 is a prime.

It is a super-3 number, since 3×128215849³ (a number of 25 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (128215889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64107924 + 64107925.

It is an arithmetic number, because the mean of its divisors is an integer number (64107925).

Almost surely, 2^128215849 is an apocalyptic number.

It is an amenable number.

128215849 is a deficient number, since it is larger than the sum of its proper divisors (1).

128215849 is an equidigital number, since it uses as much as digits as its factorization.

128215849 is an evil number, because the sum of its binary digits is even.

The product of its digits is 46080, while the sum is 40.

The square root of 128215849 is about 11323.2437490323. The cubic root of 128215849 is about 504.2515449322.

The spelling of 128215849 in words is "one hundred twenty-eight million, two hundred fifteen thousand, eight hundred forty-nine".