21313213444 has 24 divisors (see below), whose sum is σ = 39799017440. Its totient is φ = 9957432384.

The previous prime is 21313213433. The next prime is 21313213483. The reversal of 21313213444 is 44431231312.

It is a happy number.

It is a super-2 number, since 2×21313213444² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1915254 + ... + 1926349.

Almost surely, 2^21313213444 is an apocalyptic number.

It is an amenable number.

21313213444 is a deficient number, since it is larger than the sum of its proper divisors (18485803996).

21313213444 is a wasteful number, since it uses less digits than its factorization.

21313213444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3841699 (or 3841697 counting only the distinct ones).

The product of its digits is 6912, while the sum is 28.

Adding to 21313213444 its reverse (44431231312), we get a palindrome (65744444756).

It can be divided in two parts, 213132 and 13444, that added together give a square (226576 = 476²).

The spelling of 21313213444 in words is "twenty-one billion, three hundred thirteen million, two hundred thirteen thousand, four hundred forty-four".