21822181840 has 40 divisors (see below), whose sum is σ = 51693876648. Its totient is φ = 8564175360.

The previous prime is 21822181813. The next prime is 21822181847. The reversal of 21822181840 is 4818122812.

It can be written as a sum of positive squares in 4 ways, for example, as 4072481856 + 17749699984 = 63816^2 + 133228^2 .

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

It is a self number, because there is not a number n which added to its sum of digits gives 21822181840.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21822181847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2569131 + ... + 2577610.

Almost surely, 2^21822181840 is an apocalyptic number.

21822181840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21822181840 is an abundant number, since it is smaller than the sum of its proper divisors (29871694808).

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

21822181840 is a wasteful number, since it uses less digits than its factorization.

21822181840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5146807 (or 5146801 counting only the distinct ones).

The product of its (nonzero) digits is 16384, while the sum is 37.

The spelling of 21822181840 in words is "twenty-one billion, eight hundred twenty-two million, one hundred eighty-one thousand, eight hundred forty".