21442023415621 has 2 divisors, whose sum is σ = 21442023415622. Its totient is φ = 21442023415620.

The previous prime is 21442023415613. The next prime is 21442023415723. The reversal of 21442023415621 is 12651432024412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21193924786596 + 248098629025 = 4603686^2 + 498095^2 .

It is a cyclic number.

It is not a de Polignac number, because 21442023415621 - 2³ = 21442023415613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21442023115621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10721011707810 + 10721011707811.

It is an arithmetic number, because the mean of its divisors is an integer number (10721011707811).

Almost surely, 2^{21442023415621} is an apocalyptic number.

It is an amenable number.

21442023415621 is a deficient number, since it is larger than the sum of its proper divisors (1).

21442023415621 is an equidigital number, since it uses as much as digits as its factorization.

21442023415621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 92160, while the sum is 37.

The spelling of 21442023415621 in words is "twenty-one trillion, four hundred forty-two billion, twenty-three million, four hundred fifteen thousand, six hundred twenty-one".