61138275661 has 2 divisors, whose sum is σ = 61138275662. Its totient is φ = 61138275660.

The previous prime is 61138275623. The next prime is 61138275707. The reversal of 61138275661 is 16657283116.

It is a happy number.

It is an a-pointer prime, because the next prime (61138275707) can be obtained adding 61138275661 to its sum of digits (46).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 40634899561 + 20503376100 = 201581^2 + 143190^2 .

It is a cyclic number.

It is not a de Polignac number, because 61138275661 - 2¹¹ = 61138273613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61138272661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30569137830 + 30569137831.

It is an arithmetic number, because the mean of its divisors is an integer number (30569137831).

Almost surely, 2^61138275661 is an apocalyptic number.

It is an amenable number.

61138275661 is a deficient number, since it is larger than the sum of its proper divisors (1).

61138275661 is an equidigital number, since it uses as much as digits as its factorization.

61138275661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 362880, while the sum is 46.

The spelling of 61138275661 in words is "sixty-one billion, one hundred thirty-eight million, two hundred seventy-five thousand, six hundred sixty-one".