18222731 has 2 divisors, whose sum is σ = 18222732. Its totient is φ = 18222730.

The previous prime is 18222707. The next prime is 18222749. The reversal of 18222731 is 13722281.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18222731 - 2⁶ = 18222667 is a prime.

It is a super-2 number, since 2×18222731² = 664135850196722, which contains 22 as substring.

It is equal to p_1164581 and since 18222731 and 1164581 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18222731.

It is not a weakly prime, because it can be changed into another prime (18222751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9111365 + 9111366.

It is an arithmetic number, because the mean of its divisors is an integer number (9111366).

Almost surely, 2^18222731 is an apocalyptic number.

18222731 is a deficient number, since it is larger than the sum of its proper divisors (1).

18222731 is an equidigital number, since it uses as much as digits as its factorization.

18222731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1344, while the sum is 26.

The square root of 18222731 is about 4268.8090845106. The cubic root of 18222731 is about 263.1506748398.

The spelling of 18222731 in words is "eighteen million, two hundred twenty-two thousand, seven hundred thirty-one".