61386581 has 2 divisors, whose sum is σ = 61386582. Its totient is φ = 61386580.

The previous prime is 61386527. The next prime is 61386583. The reversal of 61386581 is 18568316.

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., 49928356 + 11458225 = 7066^2 + 3385^2 .

It is a cyclic number.

It is not a de Polignac number, because 61386581 - 2¹⁰ = 61385557 is a prime.

It is a super-2 number, since 2×61386581² = 7536624653739122, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 61386583, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61386583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30693290 + 30693291.

It is an arithmetic number, because the mean of its divisors is an integer number (30693291).

Almost surely, 2^61386581 is an apocalyptic number.

It is an amenable number.

61386581 is a deficient number, since it is larger than the sum of its proper divisors (1).

61386581 is an equidigital number, since it uses as much as digits as its factorization.

61386581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34560, while the sum is 38.

The square root of 61386581 is about 7834.9589022534. The cubic root of 61386581 is about 394.4795388526.

The spelling of 61386581 in words is "sixty-one million, three hundred eighty-six thousand, five hundred eighty-one".