61546665709 has 2 divisors, whose sum is σ = 61546665710. Its totient is φ = 61546665708.

The previous prime is 61546665647. The next prime is 61546665721. The reversal of 61546665709 is 90756664516.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61514912484 + 31753225 = 248022^2 + 5635^2 .

It is a cyclic number.

It is not a de Polignac number, because 61546665709 - 2¹⁹ = 61546141421 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 61546665709.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61546665209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30773332854 + 30773332855.

It is an arithmetic number, because the mean of its divisors is an integer number (30773332855).

Almost surely, 2^61546665709 is an apocalyptic number.

It is an amenable number.

61546665709 is a deficient number, since it is larger than the sum of its proper divisors (1).

61546665709 is an equidigital number, since it uses as much as digits as its factorization.

61546665709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8164800, while the sum is 55.

The spelling of 61546665709 in words is "sixty-one billion, five hundred forty-six million, six hundred sixty-five thousand, seven hundred nine".