218290909840 has 40 divisors (see below), whose sum is σ = 521243301240. Its totient is φ = 84956461056.

The previous prime is 218290909831. The next prime is 218290909861. The reversal of 218290909840 is 48909092812.

It can be written as a sum of positive squares in 4 ways, for example, as 55565804176 + 162725105664 = 235724^2 + 403392^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36870505 + ... + 36876424.

It is an arithmetic number, because the mean of its divisors is an integer number (13031082531).

Almost surely, 2^218290909840 is an apocalyptic number.

218290909840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

218290909840 is an abundant number, since it is smaller than the sum of its proper divisors (302952391400).

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

218290909840 is a wasteful number, since it uses less digits than its factorization.

218290909840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73746979 (or 73746973 counting only the distinct ones).

The product of its (nonzero) digits is 746496, while the sum is 52.

The spelling of 218290909840 in words is "two hundred eighteen billion, two hundred ninety million, nine hundred nine thousand, eight hundred forty".