21411550973 has 2 divisors, whose sum is σ = 21411550974. Its totient is φ = 21411550972.

The previous prime is 21411550969. The next prime is 21411550999. The reversal of 21411550973 is 37905511412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17816109529 + 3595441444 = 133477^2 + 59962^2 .

It is a cyclic number.

It is not a de Polignac number, because 21411550973 - 2² = 21411550969 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21411550373) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10705775486 + 10705775487.

It is an arithmetic number, because the mean of its divisors is an integer number (10705775487).

Almost surely, 2^21411550973 is an apocalyptic number.

It is an amenable number.

21411550973 is a deficient number, since it is larger than the sum of its proper divisors (1).

21411550973 is an equidigital number, since it uses as much as digits as its factorization.

21411550973 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 37800, while the sum is 38.

The spelling of 21411550973 in words is "twenty-one billion, four hundred eleven million, five hundred fifty thousand, nine hundred seventy-three".