55561060105991 has 4 divisors (see below), whose sum is σ = 60612065570184. Its totient is φ = 50510054641800.

The previous prime is 55561060105979. The next prime is 55561060106021. The reversal of 55561060105991 is 19950106016555.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 55561060105991 - 2¹⁸ = 55561059843847 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55561060105931) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2525502732080 + ... + 2525502732101.

It is an arithmetic number, because the mean of its divisors is an integer number (15153016392546).

Almost surely, 2^{55561060105991} is an apocalyptic number.

55561060105991 is a deficient number, since it is larger than the sum of its proper divisors (5051005464193).

55561060105991 is a wasteful number, since it uses less digits than its factorization.

55561060105991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5051005464192.

The product of its (nonzero) digits is 1822500, while the sum is 53.

The spelling of 55561060105991 in words is "fifty-five trillion, five hundred sixty-one billion, sixty million, one hundred five thousand, nine hundred ninety-one".