55218161820 has 24 divisors (see below), whose sum is σ = 154610853264. Its totient is φ = 14724843136.

The previous prime is 55218161783. The next prime is 55218161821. The reversal of 55218161820 is 2816181255.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55218161821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 460151289 + ... + 460151408.

It is an arithmetic number, because the mean of its divisors is an integer number (6442118886).

Almost surely, 2^55218161820 is an apocalyptic number.

It is an amenable number.

55218161820 is an abundant number, since it is smaller than the sum of its proper divisors (99392691444).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

55218161820 is a wasteful number, since it uses less digits than its factorization.

55218161820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 920302709 (or 920302707 counting only the distinct ones).

The product of its (nonzero) digits is 38400, while the sum is 39.

The spelling of 55218161820 in words is "fifty-five billion, two hundred eighteen million, one hundred sixty-one thousand, eight hundred twenty".