21616205066644 has 24 divisors (see below), whose sum is σ = 37902301673600. Its totient is φ = 10786996644480.

The previous prime is 21616205066627. The next prime is 21616205066647. The reversal of 21616205066644 is 44666050261612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21616205066647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1615999 + ... + 6770809.

Almost surely, 2^{21616205066644} is an apocalyptic number.

It is an amenable number.

21616205066644 is a deficient number, since it is larger than the sum of its proper divisors (16286096606956).

21616205066644 is a wasteful number, since it uses less digits than its factorization.

21616205066644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5156863 (or 5156861 counting only the distinct ones).

The product of its (nonzero) digits is 2488320, while the sum is 49.

The spelling of 21616205066644 in words is "twenty-one trillion, six hundred sixteen billion, two hundred five million, sixty-six thousand, six hundred forty-four".