21221546645641 has 8 divisors (see below), whose sum is σ = 22482038557440. Its totient is φ = 19962406471488.

The previous prime is 21221546645633. The next prime is 21221546645657. The reversal of 21221546645641 is 14654664512212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21221546645641 - 2³ = 21221546645633 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21221546645441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 337902081 + ... + 337964878.

It is an arithmetic number, because the mean of its divisors is an integer number (2810254819680).

Almost surely, 2^{21221546645641} is an apocalyptic number.

It is an amenable number.

21221546645641 is a deficient number, since it is larger than the sum of its proper divisors (1260491911799).

21221546645641 is a wasteful number, since it uses less digits than its factorization.

21221546645641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 675868823.

The product of its digits is 2764800, while the sum is 49.

The spelling of 21221546645641 in words is "twenty-one trillion, two hundred twenty-one billion, five hundred forty-six million, six hundred forty-five thousand, six hundred forty-one".