994721136640018 has 8 divisors (see below), whose sum is σ = 1492081979657148. Its totient is φ = 497360476754304.

The previous prime is 994721136639961. The next prime is 994721136640019. The reversal of 994721136640018 is 810046631127499.

It can be written as a sum of positive squares in 2 ways, for example, as 989767275961489 + 4953860678529 = 31460567^2 + 2225727^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (994721136640019) 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, 31285371 + ... + 54481342.

Almost surely, 2^{994721136640018} is an apocalyptic number.

994721136640018 is a deficient number, since it is larger than the sum of its proper divisors (497360843017130).

994721136640018 is a wasteful number, since it uses less digits than its factorization.

994721136640018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91565708.

The product of its (nonzero) digits is 15676416, while the sum is 61.

The spelling of 994721136640018 in words is "nine hundred ninety-four trillion, seven hundred twenty-one billion, one hundred thirty-six million, six hundred forty thousand, eighteen".