18721750001 has 2 divisors, whose sum is σ = 18721750002. Its totient is φ = 18721750000.

The previous prime is 18721749911. The next prime is 18721750079. The reversal of 18721750001 is 10005712781.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15116948401 + 3604801600 = 122951^2 + 60040^2 .

It is an emirp because it is prime and its reverse (10005712781) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18721750001 - 2¹⁰ = 18721748977 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18721750001.

It is not a weakly prime, because it can be changed into another prime (18721710001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9360875000 + 9360875001.

It is an arithmetic number, because the mean of its divisors is an integer number (9360875001).

Almost surely, 2^18721750001 is an apocalyptic number.

It is an amenable number.

18721750001 is a deficient number, since it is larger than the sum of its proper divisors (1).

18721750001 is an equidigital number, since it uses as much as digits as its factorization.

18721750001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3920, while the sum is 32.

The spelling of 18721750001 in words is "eighteen billion, seven hundred twenty-one million, seven hundred fifty thousand, one".