7318221973 has 2 divisors, whose sum is σ = 7318221974. Its totient is φ = 7318221972.

The previous prime is 7318221961. The next prime is 7318221983. The reversal of 7318221973 is 3791228137.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4975468369 + 2342753604 = 70537^2 + 48402^2 .

It is a cyclic number.

It is not a de Polignac number, because 7318221973 - 2⁹ = 7318221461 is a prime.

It is a super-2 number, since 2×7318221973² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7318221983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3659110986 + 3659110987.

It is an arithmetic number, because the mean of its divisors is an integer number (3659110987).

Almost surely, 2^7318221973 is an apocalyptic number.

It is an amenable number.

7318221973 is a deficient number, since it is larger than the sum of its proper divisors (1).

7318221973 is an equidigital number, since it uses as much as digits as its factorization.

7318221973 is an evil number, because the sum of its binary digits is even.

The product of its digits is 127008, while the sum is 43.

The square root of 7318221973 is about 85546.6070221374. The cubic root of 7318221973 is about 1941.4901553490.

The spelling of 7318221973 in words is "seven billion, three hundred eighteen million, two hundred twenty-one thousand, nine hundred seventy-three".