21841841641 has 2 divisors, whose sum is σ = 21841841642. Its totient is φ = 21841841640.

The previous prime is 21841841611. The next prime is 21841841699. The reversal of 21841841641 is 14614814812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21777200041 + 64641600 = 147571^2 + 8040^2 .

It is a cyclic number.

It is not a de Polignac number, because 21841841641 - 2⁷ = 21841841513 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21841841594 and 21841841603.

It is not a weakly prime, because it can be changed into another prime (21841841611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10920920820 + 10920920821.

It is an arithmetic number, because the mean of its divisors is an integer number (10920920821).

Almost surely, 2^21841841641 is an apocalyptic number.

It is an amenable number.

21841841641 is a deficient number, since it is larger than the sum of its proper divisors (1).

21841841641 is an equidigital number, since it uses as much as digits as its factorization.

21841841641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 49152, while the sum is 40.

The spelling of 21841841641 in words is "twenty-one billion, eight hundred forty-one million, eight hundred forty-one thousand, six hundred forty-one".