21621411353456 has 20 divisors (see below), whose sum is σ = 42039510953112. Its totient is φ = 10772505301056.

The previous prime is 21621411353453. The next prime is 21621411353467. The reversal of 21621411353456 is 65435311412612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21621411353453) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2387518811 + ... + 2387527866.

Almost surely, 2^{21621411353456} is an apocalyptic number.

It is an amenable number.

21621411353456 is a deficient number, since it is larger than the sum of its proper divisors (20418099599656).

21621411353456 is a wasteful number, since it uses less digits than its factorization.

21621411353456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4775046968 (or 4775046962 counting only the distinct ones).

The product of its digits is 518400, while the sum is 44.

The spelling of 21621411353456 in words is "twenty-one trillion, six hundred twenty-one billion, four hundred eleven million, three hundred fifty-three thousand, four hundred fifty-six".