128218029869 has 4 divisors (see below), whose sum is σ = 129658681980. Its totient is φ = 126777377760.

The previous prime is 128218029853. The next prime is 128218029871. The reversal of 128218029869 is 968920812821.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 34945815844 + 93272214025 = 186938^2 + 305405^2 .

It is a cyclic number.

It is not a de Polignac number, because 128218029869 - 2⁴ = 128218029853 is a prime.

It is a super-2 number, since 2×128218029869² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128218029839) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 720325922 + ... + 720326099.

It is an arithmetic number, because the mean of its divisors is an integer number (32414670495).

Almost surely, 2^128218029869 is an apocalyptic number.

It is an amenable number.

128218029869 is a deficient number, since it is larger than the sum of its proper divisors (1440652111).

128218029869 is an equidigital number, since it uses as much as digits as its factorization.

128218029869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1440652110.

The product of its (nonzero) digits is 1990656, while the sum is 56.

The spelling of 128218029869 in words is "one hundred twenty-eight billion, two hundred eighteen million, twenty-nine thousand, eight hundred sixty-nine".