1218646501 has 2 divisors, whose sum is σ = 1218646502. Its totient is φ = 1218646500.

The previous prime is 1218646489. The next prime is 1218646511. The reversal of 1218646501 is 1056468121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 948701601 + 269944900 = 30801^2 + 16430^2 .

It is an emirp because it is prime and its reverse (1056468121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1218646501 - 2¹⁵ = 1218613733 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1218646511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 609323250 + 609323251.

It is an arithmetic number, because the mean of its divisors is an integer number (609323251).

Almost surely, 2^1218646501 is an apocalyptic number.

It is an amenable number.

1218646501 is a deficient number, since it is larger than the sum of its proper divisors (1).

1218646501 is an equidigital number, since it uses as much as digits as its factorization.

1218646501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11520, while the sum is 34.

The square root of 1218646501 is about 34909.1177344831. The cubic root of 1218646501 is about 1068.1344325838.

The spelling of 1218646501 in words is "one billion, two hundred eighteen million, six hundred forty-six thousand, five hundred one".