21633177641 has 2 divisors, whose sum is σ = 21633177642. Its totient is φ = 21633177640.

The previous prime is 21633177619. The next prime is 21633177659. The reversal of 21633177641 is 14677133612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11707240000 + 9925937641 = 108200^2 + 99629^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21633177641 is a prime.

It is not a weakly prime, because it can be changed into another prime (21633177611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10816588820 + 10816588821.

It is an arithmetic number, because the mean of its divisors is an integer number (10816588821).

Almost surely, 2^21633177641 is an apocalyptic number.

It is an amenable number.

21633177641 is a deficient number, since it is larger than the sum of its proper divisors (1).

21633177641 is an equidigital number, since it uses as much as digits as its factorization.

21633177641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 127008, while the sum is 41.

The spelling of 21633177641 in words is "twenty-one billion, six hundred thirty-three million, one hundred seventy-seven thousand, six hundred forty-one".