1721323057 has 2 divisors, whose sum is σ = 1721323058. Its totient is φ = 1721323056.

The previous prime is 1721323033. The next prime is 1721323061. The reversal of 1721323057 is 7503231271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1560566016 + 160757041 = 39504^2 + 12679^2 .

It is a cyclic number.

It is not a de Polignac number, because 1721323057 - 2¹⁵ = 1721290289 is a prime.

It is not a weakly prime, because it can be changed into another prime (1721323007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 860661528 + 860661529.

It is an arithmetic number, because the mean of its divisors is an integer number (860661529).

Almost surely, 2^1721323057 is an apocalyptic number.

It is an amenable number.

1721323057 is a deficient number, since it is larger than the sum of its proper divisors (1).

1721323057 is an equidigital number, since it uses as much as digits as its factorization.

1721323057 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8820, while the sum is 31.

The square root of 1721323057 is about 41488.8305089454. The cubic root of 1721323057 is about 1198.4524163546.

The spelling of 1721323057 in words is "one billion, seven hundred twenty-one million, three hundred twenty-three thousand, fifty-seven".