7321406581 has 2 divisors, whose sum is σ = 7321406582. Its totient is φ = 7321406580.

The previous prime is 7321406569. The next prime is 7321406633. The reversal of 7321406581 is 1856041237.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6293883556 + 1027523025 = 79334^2 + 32055^2 .

It is an emirp because it is prime and its reverse (1856041237) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7321406581 - 2⁷ = 7321406453 is a prime.

It is a super-2 number, since 2×7321406581² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 7321406581.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7321403581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3660703290 + 3660703291.

It is an arithmetic number, because the mean of its divisors is an integer number (3660703291).

Almost surely, 2^7321406581 is an apocalyptic number.

It is an amenable number.

7321406581 is a deficient number, since it is larger than the sum of its proper divisors (1).

7321406581 is an equidigital number, since it uses as much as digits as its factorization.

7321406581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40320, while the sum is 37.

The square root of 7321406581 is about 85565.2182899103. The cubic root of 7321406581 is about 1941.7717350583.

The spelling of 7321406581 in words is "seven billion, three hundred twenty-one million, four hundred six thousand, five hundred eighty-one".