9918720001 has 4 divisors (see below), whose sum is σ = 10149387952. Its totient is φ = 9688052052.

The previous prime is 9918719971. The next prime is 9918720017. The reversal of 9918720001 is 1000278199.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1000278199 = 19 ⋅52646221.

It is a cyclic number.

It is not a de Polignac number, because 9918720001 - 2⁷ = 9918719873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9918720901) 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, 115333911 + ... + 115333996.

It is an arithmetic number, because the mean of its divisors is an integer number (2537346988).

Almost surely, 2^9918720001 is an apocalyptic number.

It is an amenable number.

9918720001 is a deficient number, since it is larger than the sum of its proper divisors (230667951).

9918720001 is a wasteful number, since it uses less digits than its factorization.

9918720001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230667950.

The product of its (nonzero) digits is 9072, while the sum is 37.

The square root of 9918720001 is about 99592.7708270033. The cubic root of 9918720001 is about 2148.5817219828.

The spelling of 9918720001 in words is "nine billion, nine hundred eighteen million, seven hundred twenty thousand, one".