1764825721 has 2 divisors, whose sum is σ = 1764825722. Its totient is φ = 1764825720.

The previous prime is 1764825679. The next prime is 1764825731. The reversal of 1764825721 is 1275284671.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1565310096 + 199515625 = 39564^2 + 14125^2 .

It is an emirp because it is prime and its reverse (1275284671) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1764825721 - 2¹⁹ = 1764301433 is a prime.

It is a super-2 number, since 2×1764825721² = 6229219651006339682, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1764825731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 882412860 + 882412861.

It is an arithmetic number, because the mean of its divisors is an integer number (882412861).

Almost surely, 2^1764825721 is an apocalyptic number.

It is an amenable number.

1764825721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1764825721 is an equidigital number, since it uses as much as digits as its factorization.

1764825721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 188160, while the sum is 43.

The square root of 1764825721 is about 42009.8288618271. The cubic root of 1764825721 is about 1208.4646238486.

The spelling of 1764825721 in words is "one billion, seven hundred sixty-four million, eight hundred twenty-five thousand, seven hundred twenty-one".