61959039581 has 2 divisors, whose sum is σ = 61959039582. Its totient is φ = 61959039580.

The previous prime is 61959039557. The next prime is 61959039587. The reversal of 61959039581 is 18593095916.

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., 52420392025 + 9538647556 = 228955^2 + 97666^2 .

It is a cyclic number.

It is not a de Polignac number, because 61959039581 - 2⁶ = 61959039517 is a prime.

It is a super-2 number, since 2×61959039581² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61959039587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30979519790 + 30979519791.

It is an arithmetic number, because the mean of its divisors is an integer number (30979519791).

Almost surely, 2^61959039581 is an apocalyptic number.

It is an amenable number.

61959039581 is a deficient number, since it is larger than the sum of its proper divisors (1).

61959039581 is an equidigital number, since it uses as much as digits as its factorization.

61959039581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2624400, while the sum is 56.

The spelling of 61959039581 in words is "sixty-one billion, nine hundred fifty-nine million, thirty-nine thousand, five hundred eighty-one".