21015404445 has 48 divisors (see below), whose sum is σ = 39852466560. Its totient is φ = 9425759616.

The previous prime is 21015404419. The next prime is 21015404453. The reversal of 21015404445 is 54440451012.

It is not a de Polignac number, because 21015404445 - 2¹² = 21015400349 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 230785 + ... + 308694.

It is an arithmetic number, because the mean of its divisors is an integer number (830259720).

Almost surely, 2^21015404445 is an apocalyptic number.

It is an amenable number.

21015404445 is a deficient number, since it is larger than the sum of its proper divisors (18837062115).

21015404445 is a wasteful number, since it uses less digits than its factorization.

21015404445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 539554 (or 539547 counting only the distinct ones).

The product of its (nonzero) digits is 12800, while the sum is 30.

Adding to 21015404445 its reverse (54440451012), we get a palindrome (75455855457).

The spelling of 21015404445 in words is "twenty-one billion, fifteen million, four hundred four thousand, four hundred forty-five".