21531441212 has 12 divisors (see below), whose sum is σ = 39663181320. Its totient is φ = 10199103696.

The previous prime is 21531441209. The next prime is 21531441263. The reversal of 21531441212 is 21214413512.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 141654143 + ... + 141654294.

It is an arithmetic number, because the mean of its divisors is an integer number (3305265110).

Almost surely, 2^21531441212 is an apocalyptic number.

It is an amenable number.

21531441212 is a deficient number, since it is larger than the sum of its proper divisors (18131740108).

21531441212 is a wasteful number, since it uses less digits than its factorization.

21531441212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283308460 (or 283308458 counting only the distinct ones).

The product of its digits is 1920, while the sum is 26.

Adding to 21531441212 its reverse (21214413512), we get a palindrome (42745854724).

The spelling of 21531441212 in words is "twenty-one billion, five hundred thirty-one million, four hundred forty-one thousand, two hundred twelve".