21162401173 has 2 divisors, whose sum is σ = 21162401174. Its totient is φ = 21162401172.

The previous prime is 21162401147. The next prime is 21162401179. The reversal of 21162401173 is 37110426112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20299980484 + 862420689 = 142478^2 + 29367^2 .

It is a cyclic number.

It is not a de Polignac number, because 21162401173 - 2³³ = 12572466581 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21162401179) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10581200586 + 10581200587.

It is an arithmetic number, because the mean of its divisors is an integer number (10581200587).

Almost surely, 2^21162401173 is an apocalyptic number.

It is an amenable number.

21162401173 is a deficient number, since it is larger than the sum of its proper divisors (1).

21162401173 is an equidigital number, since it uses as much as digits as its factorization.

21162401173 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 28.

Adding to 21162401173 its reverse (37110426112), we get a palindrome (58272827285).

The spelling of 21162401173 in words is "twenty-one billion, one hundred sixty-two million, four hundred one thousand, one hundred seventy-three".