21623817239641 has 2 divisors, whose sum is σ = 21623817239642. Its totient is φ = 21623817239640.

The previous prime is 21623817239533. The next prime is 21623817239711. The reversal of 21623817239641 is 14693271832612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17919812912400 + 3704004327241 = 4233180^2 + 1924579^2 .

It is a cyclic number.

It is not a de Polignac number, because 21623817239641 - 2⁴³ = 12827724217433 is a prime.

It is a super-3 number, since 3×21623817239641³ (a number of 41 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (21623817209641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10811908619820 + 10811908619821.

It is an arithmetic number, because the mean of its divisors is an integer number (10811908619821).

Almost surely, 2^{21623817239641} is an apocalyptic number.

It is an amenable number.

21623817239641 is a deficient number, since it is larger than the sum of its proper divisors (1).

21623817239641 is an equidigital number, since it uses as much as digits as its factorization.

21623817239641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5225472, while the sum is 55.

The spelling of 21623817239641 in words is "twenty-one trillion, six hundred twenty-three billion, eight hundred seventeen million, two hundred thirty-nine thousand, six hundred forty-one".