21585623672 has 8 divisors (see below), whose sum is σ = 40473044400. Its totient is φ = 10792811832.

The previous prime is 21585623659. The next prime is 21585623677. The reversal of 21585623672 is 27632658512.

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 (21585623677) 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, 1349101472 + ... + 1349101487.

It is an arithmetic number, because the mean of its divisors is an integer number (5059130550).

Almost surely, 2^21585623672 is an apocalyptic number.

It is an amenable number.

21585623672 is a deficient number, since it is larger than the sum of its proper divisors (18887420728).

21585623672 is a wasteful number, since it uses less digits than its factorization.

21585623672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2698202965 (or 2698202961 counting only the distinct ones).

The product of its digits is 1209600, while the sum is 47.

The spelling of 21585623672 in words is "twenty-one billion, five hundred eighty-five million, six hundred twenty-three thousand, six hundred seventy-two".