18764321 has 2 divisors, whose sum is σ = 18764322. Its totient is φ = 18764320.

The previous prime is 18764303. The next prime is 18764329. The reversal of 18764321 is 12346781.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10144225 + 8620096 = 3185^2 + 2936^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18764321 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18764329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9382160 + 9382161.

It is an arithmetic number, because the mean of its divisors is an integer number (9382161).

Almost surely, 2^18764321 is an apocalyptic number.

It is an amenable number.

18764321 is a deficient number, since it is larger than the sum of its proper divisors (1).

18764321 is an equidigital number, since it uses as much as digits as its factorization.

18764321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8064, while the sum is 32.

The square root of 18764321 is about 4331.7803499254. The cubic root of 18764321 is about 265.7322621201.

The spelling of 18764321 in words is "eighteen million, seven hundred sixty-four thousand, three hundred twenty-one".