61661666011559 has 2 divisors, whose sum is σ = 61661666011560. Its totient is φ = 61661666011558.

The previous prime is 61661666011499. The next prime is 61661666011609. The reversal of 61661666011559 is 95511066616616.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61661666011559 is a prime.

It is a super-2 number, since 2×61661666011559² (a number of 28 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 61661666011498 and 61661666011507.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61661666011459) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30830833005779 + 30830833005780.

It is an arithmetic number, because the mean of its divisors is an integer number (30830833005780).

Almost surely, 2^{61661666011559} is an apocalyptic number.

61661666011559 is a deficient number, since it is larger than the sum of its proper divisors (1).

61661666011559 is an equidigital number, since it uses as much as digits as its factorization.

61661666011559 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10497600, while the sum is 59.

The spelling of 61661666011559 in words is "sixty-one trillion, six hundred sixty-one billion, six hundred sixty-six million, eleven thousand, five hundred fifty-nine".