994128505505 has 4 divisors (see below), whose sum is σ = 1192954206612. Its totient is φ = 795302804400.

The previous prime is 994128505481. The next prime is 994128505547. The reversal of 994128505505 is 505505821499.

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 515580005521 + 478548499984 = 718039^2 + 691772^2 .

It is not a de Polignac number, because 994128505505 - 2⁶ = 994128505441 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 99412850546 + ... + 99412850555.

It is an arithmetic number, because the mean of its divisors is an integer number (298238551653).

Almost surely, 2^994128505505 is an apocalyptic number.

It is an amenable number.

994128505505 is a deficient number, since it is larger than the sum of its proper divisors (198825701107).

994128505505 is a wasteful number, since it uses less digits than its factorization.

994128505505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198825701106.

The product of its (nonzero) digits is 3240000, while the sum is 53.

The spelling of 994128505505 in words is "nine hundred ninety-four billion, one hundred twenty-eight million, five hundred five thousand, five hundred five".