21353021444 has 6 divisors (see below), whose sum is σ = 37367787534. Its totient is φ = 10676510720.

The previous prime is 21353021323. The next prime is 21353021447. The reversal of 21353021444 is 44412035312.

It can be written as a sum of positive squares in only one way, i.e., 11687772100 + 9665249344 = 108110^2 + 98312^2 .

It is not an unprimeable number, because it can be changed into a prime (21353021447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2669127677 + ... + 2669127684.

It is an arithmetic number, because the mean of its divisors is an integer number (6227964589).

Almost surely, 2^21353021444 is an apocalyptic number.

It is an amenable number.

21353021444 is a deficient number, since it is larger than the sum of its proper divisors (16014766090).

21353021444 is a wasteful number, since it uses less digits than its factorization.

21353021444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5338255365 (or 5338255363 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 29.

Adding to 21353021444 its reverse (44412035312), we get a palindrome (65765056756).

The spelling of 21353021444 in words is "twenty-one billion, three hundred fifty-three million, twenty-one thousand, four hundred forty-four".