73218331 has 2 divisors, whose sum is σ = 73218332. Its totient is φ = 73218330.

The previous prime is 73218329. The next prime is 73218347. The reversal of 73218331 is 13381237.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 73218331 - 2¹ = 73218329 is a prime.

It is a super-2 number, since 2×73218331² = 10721847988851122, which contains 22 as substring.

Together with 73218329, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 73218331.

It is not a weakly prime, because it can be changed into another prime (73218391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36609165 + 36609166.

It is an arithmetic number, because the mean of its divisors is an integer number (36609166).

Almost surely, 2^73218331 is an apocalyptic number.

73218331 is a deficient number, since it is larger than the sum of its proper divisors (1).

73218331 is an equidigital number, since it uses as much as digits as its factorization.

73218331 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 28.

The square root of 73218331 is about 8556.7710615629. The cubic root of 73218331 is about 418.3501621599.

Adding to 73218331 its reverse (13381237), we get a palindrome (86599568).

The spelling of 73218331 in words is "seventy-three million, two hundred eighteen thousand, three hundred thirty-one".