21601553332645 has 24 divisors (see below), whose sum is σ = 30620986211232. Its totient is φ = 14501742091200.

The previous prime is 21601553332613. The next prime is 21601553332679. The reversal of 21601553332645 is 54623335510612.

It is not a de Polignac number, because 21601553332645 - 2⁵ = 21601553332613 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21601553332595 and 21601553332604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1161989271 + ... + 1162007860.

It is an arithmetic number, because the mean of its divisors is an integer number (1275874425468).

Almost surely, 2^{21601553332645} is an apocalyptic number.

It is an amenable number.

21601553332645 is a deficient number, since it is larger than the sum of its proper divisors (9019432878587).

21601553332645 is a wasteful number, since it uses less digits than its factorization.

21601553332645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2323997173 (or 2323997160 counting only the distinct ones).

The product of its (nonzero) digits is 1944000, while the sum is 46.

The spelling of 21601553332645 in words is "twenty-one trillion, six hundred one billion, five hundred fifty-three million, three hundred thirty-two thousand, six hundred forty-five".