21023020444 has 6 divisors (see below), whose sum is σ = 36790285784. Its totient is φ = 10511510220.

The previous prime is 21023020433. The next prime is 21023020483. The reversal of 21023020444 is 44402032012.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2627877552 + ... + 2627877559.

Almost surely, 2^21023020444 is an apocalyptic number.

It is an amenable number.

21023020444 is a deficient number, since it is larger than the sum of its proper divisors (15767265340).

21023020444 is a wasteful number, since it uses less digits than its factorization.

21023020444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5255755115 (or 5255755113 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 22.

Adding to 21023020444 its reverse (44402032012), we get a palindrome (65425052456).

The spelling of 21023020444 in words is "twenty-one billion, twenty-three million, twenty thousand, four hundred forty-four".