21012213443 has 8 divisors (see below), whose sum is σ = 22629859728. Its totient is φ = 19394756064.

The previous prime is 21012213403. The next prime is 21012213473. The reversal of 21012213443 is 34431221012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21012213443 - 2¹⁸ = 21011951299 is a prime.

It is a super-2 number, since 2×21012213443² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21012213403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 255896 + ... + 327882.

It is an arithmetic number, because the mean of its divisors is an integer number (2828732466).

Almost surely, 2^21012213443 is an apocalyptic number.

21012213443 is a deficient number, since it is larger than the sum of its proper divisors (1617646285).

21012213443 is a wasteful number, since it uses less digits than its factorization.

21012213443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94453.

The product of its (nonzero) digits is 1152, while the sum is 23.

Adding to 21012213443 its reverse (34431221012), we get a palindrome (55443434455).

The spelling of 21012213443 in words is "twenty-one billion, twelve million, two hundred thirteen thousand, four hundred forty-three".