21456633531641 has 16 divisors (see below), whose sum is σ = 26751229596288. Its totient is φ = 16719390902400.

The previous prime is 21456633531637. The next prime is 21456633531649. The reversal of 21456633531641 is 14613533665412.

It is a cyclic number.

It is not a de Polignac number, because 21456633531641 - 2² = 21456633531637 is a prime.

It is a super-2 number, since 2×21456633531641² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21456633531641.

It is not an unprimeable number, because it can be changed into a prime (21456633531649) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35775011 + ... + 36369831.

It is an arithmetic number, because the mean of its divisors is an integer number (1671951849768).

Almost surely, 2^{21456633531641} is an apocalyptic number.

It is an amenable number.

21456633531641 is a deficient number, since it is larger than the sum of its proper divisors (5294596064647).

21456633531641 is a wasteful number, since it uses less digits than its factorization.

21456633531641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1063312.

The product of its digits is 4665600, while the sum is 50.

The spelling of 21456633531641 in words is "twenty-one trillion, four hundred fifty-six billion, six hundred thirty-three million, five hundred thirty-one thousand, six hundred forty-one".