128220026731 has 4 divisors (see below), whose sum is σ = 128303777464. Its totient is φ = 128136276000.

The previous prime is 128220026713. The next prime is 128220026743. The reversal of 128220026731 is 137620022821.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 128220026731 - 2¹³ = 128220018539 is a prime.

It is a super-2 number, since 2×128220026731² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128220021731) 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, 41873070 + ... + 41876131.

It is an arithmetic number, because the mean of its divisors is an integer number (32075944366).

Almost surely, 2^128220026731 is an apocalyptic number.

128220026731 is a deficient number, since it is larger than the sum of its proper divisors (83750733).

128220026731 is an equidigital number, since it uses as much as digits as its factorization.

128220026731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83750732.

The product of its (nonzero) digits is 16128, while the sum is 34.

The spelling of 128220026731 in words is "one hundred twenty-eight billion, two hundred twenty million, twenty-six thousand, seven hundred thirty-one".