55518389781 has 16 divisors (see below), whose sum is σ = 74183129856. Its totient is φ = 36933014016.

The previous prime is 55518389741. The next prime is 55518389789. The reversal of 55518389781 is 18798381555.

It is not a de Polignac number, because 55518389781 - 2³¹ = 53370906133 is a prime.

It is a super-2 number, since 2×55518389781² (a number of 22 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55518389789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4820676 + ... + 4832178.

It is an arithmetic number, because the mean of its divisors is an integer number (4636445616).

Almost surely, 2^55518389781 is an apocalyptic number.

It is an amenable number.

55518389781 is a deficient number, since it is larger than the sum of its proper divisors (18664740075).

55518389781 is a wasteful number, since it uses less digits than its factorization.

55518389781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14812.

The product of its digits is 12096000, while the sum is 60.

The spelling of 55518389781 in words is "fifty-five billion, five hundred eighteen million, three hundred eighty-nine thousand, seven hundred eighty-one".