18303746621 has 2 divisors, whose sum is σ = 18303746622. Its totient is φ = 18303746620.

The previous prime is 18303746581. The next prime is 18303746639. The reversal of 18303746621 is 12664730381.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16546963225 + 1756783396 = 128635^2 + 41914^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18303746621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18303746651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9151873310 + 9151873311.

It is an arithmetic number, because the mean of its divisors is an integer number (9151873311).

Almost surely, 2^18303746621 is an apocalyptic number.

It is an amenable number.

18303746621 is a deficient number, since it is larger than the sum of its proper divisors (1).

18303746621 is an equidigital number, since it uses as much as digits as its factorization.

18303746621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 145152, while the sum is 41.

The spelling of 18303746621 in words is "eighteen billion, three hundred three million, seven hundred forty-six thousand, six hundred twenty-one".