21021121044442 has 8 divisors (see below), whose sum is σ = 33386486364756. Its totient is φ = 9892292256192.

The previous prime is 21021121044401. The next prime is 21021121044449. The reversal of 21021121044442 is 24444012112012.

It can be written as a sum of positive squares in 2 ways, for example, as 19872685178641 + 1148435865801 = 4457879^2 + 1071651^2 .

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

It is a self number, because there is not a number n which added to its sum of digits gives 21021121044442.

It is not an unprimeable number, because it can be changed into a prime (21021121044449) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 309134132973 + ... + 309134133040.

Almost surely, 2^{21021121044442} is an apocalyptic number.

21021121044442 is a deficient number, since it is larger than the sum of its proper divisors (12365365320314).

21021121044442 is a wasteful number, since it uses less digits than its factorization.

21021121044442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 618268266032.

The product of its (nonzero) digits is 4096, while the sum is 28.

Adding to 21021121044442 its reverse (24444012112012), we get a palindrome (45465133156454).

The spelling of 21021121044442 in words is "twenty-one trillion, twenty-one billion, one hundred twenty-one million, forty-four thousand, four hundred forty-two".