128956802529 has 4 divisors (see below), whose sum is σ = 171942403376. Its totient is φ = 85971201684.

The previous prime is 128956802509. The next prime is 128956802537. The reversal of 128956802529 is 925208659821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 128956802529 - 2¹¹ = 128956800481 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128956802509) 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, 21492800419 + ... + 21492800424.

It is an arithmetic number, because the mean of its divisors is an integer number (42985600844).

Almost surely, 2^128956802529 is an apocalyptic number.

It is an amenable number.

128956802529 is a deficient number, since it is larger than the sum of its proper divisors (42985600847).

128956802529 is an equidigital number, since it uses as much as digits as its factorization.

128956802529 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42985600846.

The product of its (nonzero) digits is 6220800, while the sum is 57.

The spelling of 128956802529 in words is "one hundred twenty-eight billion, nine hundred fifty-six million, eight hundred two thousand, five hundred twenty-nine".