61326581 has 2 divisors, whose sum is σ = 61326582. Its totient is φ = 61326580.

The previous prime is 61326563. The next prime is 61326589. The reversal of 61326581 is 18562316.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 53436100 + 7890481 = 7310^2 + 2809^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61326581 is a prime.

It is a super-2 number, since 2×61326581² = 7521899074299122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61326589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30663290 + 30663291.

It is an arithmetic number, because the mean of its divisors is an integer number (30663291).

Almost surely, 2^61326581 is an apocalyptic number.

It is an amenable number.

61326581 is a deficient number, since it is larger than the sum of its proper divisors (1).

61326581 is an equidigital number, since it uses as much as digits as its factorization.

61326581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8640, while the sum is 32.

The square root of 61326581 is about 7831.1289735261. The cubic root of 61326581 is about 394.3509739039.

Adding to 61326581 its reverse (18562316), we get a palindrome (79888897).

The spelling of 61326581 in words is "sixty-one million, three hundred twenty-six thousand, five hundred eighty-one".