21443534444 has 24 divisors (see below), whose sum is σ = 39506347440. Its totient is φ = 10156152384.

The previous prime is 21443534369. The next prime is 21443534447. The reversal of 21443534444 is 44443534412.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a junction number, because it is equal to n+sod(n) for n = 21443534398 and 21443534407.

It is not an unprimeable number, because it can be changed into a prime (21443534447) 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, 836522 + ... + 861774.

It is an arithmetic number, because the mean of its divisors is an integer number (1646097810).

Almost surely, 2^21443534444 is an apocalyptic number.

It is an amenable number.

21443534444 is a deficient number, since it is larger than the sum of its proper divisors (18062812996).

21443534444 is a wasteful number, since it uses less digits than its factorization.

21443534444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36449 (or 36447 counting only the distinct ones).

The product of its digits is 368640, while the sum is 38.

The spelling of 21443534444 in words is "twenty-one billion, four hundred forty-three million, five hundred thirty-four thousand, four hundred forty-four".