21442023394109 has 2 divisors, whose sum is σ = 21442023394110. Its totient is φ = 21442023394108.

The previous prime is 21442023394087. The next prime is 21442023394147. The reversal of 21442023394109 is 90149332024412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21374671725625 + 67351668484 = 4623275^2 + 259522^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21442023394109 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21442023394109.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21442023394709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10721011697054 + 10721011697055.

It is an arithmetic number, because the mean of its divisors is an integer number (10721011697055).

Almost surely, 2^{21442023394109} is an apocalyptic number.

It is an amenable number.

21442023394109 is a deficient number, since it is larger than the sum of its proper divisors (1).

21442023394109 is an equidigital number, since it uses as much as digits as its factorization.

21442023394109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 373248, while the sum is 44.

The spelling of 21442023394109 in words is "twenty-one trillion, four hundred forty-two billion, twenty-three million, three hundred ninety-four thousand, one hundred nine".