64173121 has 2 divisors, whose sum is σ = 64173122. Its totient is φ = 64173120.

The previous prime is 64173119. The next prime is 64173149. The reversal of 64173121 is 12137146.

64173121 = 5664² + 5665².

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 32092225 + 32080896 = 5665^2 + 5664^2 .

It is a cyclic number.

It is not a de Polignac number, because 64173121 - 2¹ = 64173119 is a prime.

Together with 64173119, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (64173191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32086560 + 32086561.

It is an arithmetic number, because the mean of its divisors is an integer number (32086561).

Almost surely, 2^64173121 is an apocalyptic number.

64173121 is the 5665-th centered square number.

It is an amenable number.

64173121 is a deficient number, since it is larger than the sum of its proper divisors (1).

64173121 is an equidigital number, since it uses as much as digits as its factorization.

64173121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1008, while the sum is 25.

The square root of 64173121 is about 8010.8127552702. The cubic root of 64173121 is about 400.3603440330.

The spelling of 64173121 in words is "sixty-four million, one hundred seventy-three thousand, one hundred twenty-one".