20173465621 has 2 divisors, whose sum is σ = 20173465622. Its totient is φ = 20173465620.

The previous prime is 20173465619. The next prime is 20173465643. The reversal of 20173465621 is 12656437102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17295143121 + 2878322500 = 131511^2 + 53650^2 .

It is a cyclic number.

It is not a de Polignac number, because 20173465621 - 2¹ = 20173465619 is a prime.

Together with 20173465619, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20173465661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10086732810 + 10086732811.

It is an arithmetic number, because the mean of its divisors is an integer number (10086732811).

Almost surely, 2^20173465621 is an apocalyptic number.

It is an amenable number.

20173465621 is a deficient number, since it is larger than the sum of its proper divisors (1).

20173465621 is an equidigital number, since it uses as much as digits as its factorization.

20173465621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 60480, while the sum is 37.

The spelling of 20173465621 in words is "twenty billion, one hundred seventy-three million, four hundred sixty-five thousand, six hundred twenty-one".