61661071 has 2 divisors, whose sum is σ = 61661072. Its totient is φ = 61661070.

The previous prime is 61661059. The next prime is 61661081. The reversal of 61661071 is 17016616.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 61661071 - 2⁷ = 61660943 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61661051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30830535 + 30830536.

It is an arithmetic number, because the mean of its divisors is an integer number (30830536).

Almost surely, 2^61661071 is an apocalyptic number.

61661071 is a deficient number, since it is larger than the sum of its proper divisors (1).

61661071 is an equidigital number, since it uses as much as digits as its factorization.

61661071 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1512, while the sum is 28.

The square root of 61661071 is about 7852.4563672777. The cubic root of 61661071 is about 395.0666361969.

Adding to 61661071 its reverse (17016616), we get a palindrome (78677687).

The spelling of 61661071 in words is "sixty-one million, six hundred sixty-one thousand, seventy-one".