128500023961 has 27 divisors (see below), whose sum is σ = 136494654751. Its totient is φ = 120967514864.

The previous prime is 128500023947. The next prime is 128500023989. The reversal of 128500023961 is 169320005821.

The square root of 128500023961 is 358469.

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

It can be written as a sum of positive squares in only one way, i.e., 67382295561 + 61117728400 = 259581^2 + 247220^2 .

It is a de Polignac number, because none of the positive numbers 2^k-128500023961 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 128500023961.

It is not an unprimeable number, because it can be changed into a prime (128500023931) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 488593116 + ... + 488593378.

Almost surely, 2^128500023961 is an apocalyptic number.

128500023961 is the 358469-th square number.

128500023961 is the 179235-th centered octagonal number.

It is an amenable number.

128500023961 is a deficient number, since it is larger than the sum of its proper divisors (7994630790).

128500023961 is an frugal number, since it uses more digits than its factorization.

128500023961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 678 (or 339 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 37.

The spelling of 128500023961 in words is "one hundred twenty-eight billion, five hundred million, twenty-three thousand, nine hundred sixty-one".