21501072056045 has 16 divisors (see below), whose sum is σ = 26058372734592. Its totient is φ = 17029488081600.

The previous prime is 21501072055999. The next prime is 21501072056131. The reversal of 21501072056045 is 54065027010512.

It is not a de Polignac number, because 21501072056045 - 2⁸ = 21501072055789 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6810014 + ... + 9454016.

It is an arithmetic number, because the mean of its divisors is an integer number (1628648295912).

Almost surely, 2^{21501072056045} is an apocalyptic number.

It is an amenable number.

21501072056045 is a deficient number, since it is larger than the sum of its proper divisors (4557300678547).

21501072056045 is a wasteful number, since it uses less digits than its factorization.

21501072056045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2660212.

The product of its (nonzero) digits is 84000, while the sum is 38.

Adding to 21501072056045 its reverse (54065027010512), we get a palindrome (75566099066557).

The spelling of 21501072056045 in words is "twenty-one trillion, five hundred one billion, seventy-two million, fifty-six thousand, forty-five".