55601611555661 has 2 divisors, whose sum is σ = 55601611555662. Its totient is φ = 55601611555660.

The previous prime is 55601611555547. The next prime is 55601611555709. The reversal of 55601611555661 is 16655511610655.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 39635145966025 + 15966465589636 = 6295645^2 + 3995806^2 .

It is a cyclic number.

It is not a de Polignac number, because 55601611555661 - 2³⁰ = 55600537813837 is a prime.

It is a super-2 number, since 2×55601611555661² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55601611525661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27800805777830 + 27800805777831.

It is an arithmetic number, because the mean of its divisors is an integer number (27800805777831).

Almost surely, 2^{55601611555661} is an apocalyptic number.

It is an amenable number.

55601611555661 is a deficient number, since it is larger than the sum of its proper divisors (1).

55601611555661 is an equidigital number, since it uses as much as digits as its factorization.

55601611555661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4050000, while the sum is 53.

The spelling of 55601611555661 in words is "fifty-five trillion, six hundred one billion, six hundred eleven million, five hundred fifty-five thousand, six hundred sixty-one".