55186815420 has 288 divisors, whose sum is σ = 193692897216. Its totient is φ = 12570009600.

The previous prime is 55186815419. The next prime is 55186815421. The reversal of 55186815420 is 2451868155.

55186815420 is a `hidden beast` number, since 5 + 518 + 6 + 81 + 54 + 2 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (55186815419) and next prime (55186815421).

It is a super-2 number, since 2×55186815420² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55186815421) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 27633862 + ... + 27635858.

It is an arithmetic number, because the mean of its divisors is an integer number (672544782).

Almost surely, 2^55186815420 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 55186815420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96846448608).

55186815420 is an abundant number, since it is smaller than the sum of its proper divisors (138506081796).

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

55186815420 is a wasteful number, since it uses less digits than its factorization.

55186815420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2861 (or 2856 counting only the distinct ones).

The product of its (nonzero) digits is 384000, while the sum is 45.

The spelling of 55186815420 in words is "fifty-five billion, one hundred eighty-six million, eight hundred fifteen thousand, four hundred twenty".