55561780805231 has 4 divisors (see below), whose sum is σ = 55606916290464. Its totient is φ = 55516645320000.

The previous prime is 55561780805183. The next prime is 55561780805263. The reversal of 55561780805231 is 13250808716555.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55561780805231 is a prime.

It is a super-2 number, since 2×55561780805231² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55561780805291) 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, 22567740770 + ... + 22567743231.

It is an arithmetic number, because the mean of its divisors is an integer number (13901729072616).

Almost surely, 2^{55561780805231} is an apocalyptic number.

55561780805231 is a deficient number, since it is larger than the sum of its proper divisors (45135485233).

55561780805231 is a wasteful number, since it uses less digits than its factorization.

55561780805231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45135485232.

The product of its (nonzero) digits is 10080000, while the sum is 56.

The spelling of 55561780805231 in words is "fifty-five trillion, five hundred sixty-one billion, seven hundred eighty million, eight hundred five thousand, two hundred thirty-one".