21440153531444 has 12 divisors (see below), whose sum is σ = 37592284554468. Its totient is φ = 10699500801600.

The previous prime is 21440153531441. The next prime is 21440153531473. The reversal of 21440153531444 is 44413535104412.

It can be written as a sum of positive squares in 2 ways, for example, as 2941019203600 + 18499134327844 = 1714940^2 + 4301062^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21440153531441) 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, 5143988687 + ... + 5143992854.

It is an arithmetic number, because the mean of its divisors is an integer number (3132690379539).

Almost surely, 2^{21440153531444} is an apocalyptic number.

It is an amenable number.

21440153531444 is a deficient number, since it is larger than the sum of its proper divisors (16152131023024).

21440153531444 is a wasteful number, since it uses less digits than its factorization.

21440153531444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10287982066 (or 10287982064 counting only the distinct ones).

The product of its (nonzero) digits is 460800, while the sum is 41.

Adding to 21440153531444 its reverse (44413535104412), we get a palindrome (65853688635856).

The spelling of 21440153531444 in words is "twenty-one trillion, four hundred forty billion, one hundred fifty-three million, five hundred thirty-one thousand, four hundred forty-four".