21520675544 has 8 divisors (see below), whose sum is σ = 40351266660. Its totient is φ = 10760337768.

The previous prime is 21520675541. The next prime is 21520675591. The reversal of 21520675544 is 44557602512.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21520675541) by changing a digit.

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, 1345042214 + ... + 1345042229.

Almost surely, 2^21520675544 is an apocalyptic number.

It is an amenable number.

21520675544 is a deficient number, since it is larger than the sum of its proper divisors (18830591116).

21520675544 is a wasteful number, since it uses less digits than its factorization.

21520675544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2690084449 (or 2690084445 counting only the distinct ones).

The product of its (nonzero) digits is 336000, while the sum is 41.

The spelling of 21520675544 in words is "twenty-one billion, five hundred twenty million, six hundred seventy-five thousand, five hundred forty-four".