128956401025 has 9 divisors (see below), whose sum is σ = 159908163753. Its totient is φ = 103163684400.

The previous prime is 128956401017. The next prime is 128956401029. The reversal of 128956401025 is 520104659821.

The square root of 128956401025 is 359105.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 81877816449 + 47078584576 = 286143^2 + 216976^2 .

It is not a de Polignac number, because 128956401025 - 2³ = 128956401017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128956401029) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1759615 + ... + 1831435.

Almost surely, 2^128956401025 is an apocalyptic number.

128956401025 is the 359105-th square number.

128956401025 is the 179553-rd centered octagonal number.

It is an amenable number.

128956401025 is a deficient number, since it is larger than the sum of its proper divisors (30951762728).

128956401025 is an frugal number, since it uses more digits than its factorization.

128956401025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143652 (or 71826 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 43.

The spelling of 128956401025 in words is "one hundred twenty-eight billion, nine hundred fifty-six million, four hundred one thousand, twenty-five".