21021020344 has 16 divisors (see below), whose sum is σ = 40253018400. Its totient is φ = 10286882112.

The previous prime is 21021020327. The next prime is 21021020381. The reversal of 21021020344 is 44302012012.

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 in 3 ways as a sum of consecutive naturals, for example, 27953109 + ... + 27953860.

It is an arithmetic number, because the mean of its divisors is an integer number (2515813650).

Almost surely, 2^21021020344 is an apocalyptic number.

It is an amenable number.

21021020344 is a deficient number, since it is larger than the sum of its proper divisors (19231998056).

21021020344 is a wasteful number, since it uses less digits than its factorization.

21021020344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55907022 (or 55907018 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

Adding to 21021020344 its reverse (44302012012), we get a palindrome (65323032356).

The spelling of 21021020344 in words is "twenty-one billion, twenty-one million, twenty thousand, three hundred forty-four".