61981571 has 2 divisors, whose sum is σ = 61981572. Its totient is φ = 61981570.

The previous prime is 61981561. The next prime is 61981607. The reversal of 61981571 is 17518916.

61981571 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61981571 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (61981501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30990785 + 30990786.

It is an arithmetic number, because the mean of its divisors is an integer number (30990786).

Almost surely, 2^61981571 is an apocalyptic number.

61981571 is a deficient number, since it is larger than the sum of its proper divisors (1).

61981571 is an equidigital number, since it uses as much as digits as its factorization.

61981571 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15120, while the sum is 38.

The square root of 61981571 is about 7872.8375443673. The cubic root of 61981571 is about 395.7499420365.

The spelling of 61981571 in words is "sixty-one million, nine hundred eighty-one thousand, five hundred seventy-one".