21212212144 has 10 divisors (see below), whose sum is σ = 41098661060. Its totient is φ = 10606106064.

The previous prime is 21212212061. The next prime is 21212212181. The reversal of 21212212144 is 44121221212.

It is a super-2 number, since 2×21212212144² (a number of 21 digits) contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 662881614 + ... + 662881645.

It is an arithmetic number, because the mean of its divisors is an integer number (4109866106).

Almost surely, 2^21212212144 is an apocalyptic number.

It is an amenable number.

21212212144 is a deficient number, since it is larger than the sum of its proper divisors (19886448916).

21212212144 is a wasteful number, since it uses less digits than its factorization.

21212212144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1325763267 (or 1325763261 counting only the distinct ones).

The product of its digits is 512, while the sum is 22.

Adding to 21212212144 its reverse (44121221212), we get a palindrome (65333433356).

The spelling of 21212212144 in words is "twenty-one billion, two hundred twelve million, two hundred twelve thousand, one hundred forty-four".