1764365221 has 2 divisors, whose sum is σ = 1764365222. Its totient is φ = 1764365220.

The previous prime is 1764365209. The next prime is 1764365261. The reversal of 1764365221 is 1225634671.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1614914596 + 149450625 = 40186^2 + 12225^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1764365221 is a prime.

It is a super-2 number, since 2×1764365221² = 6225969266148757682, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1764365201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 882182610 + 882182611.

It is an arithmetic number, because the mean of its divisors is an integer number (882182611).

Almost surely, 2^1764365221 is an apocalyptic number.

It is an amenable number.

1764365221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1764365221 is an equidigital number, since it uses as much as digits as its factorization.

1764365221 is an evil number, because the sum of its binary digits is even.

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

The square root of 1764365221 is about 42004.3476440237. The cubic root of 1764365221 is about 1208.3595055618.

Adding to 1764365221 its reverse (1225634671), we get a palindrome (2989999892).

The spelling of 1764365221 in words is "one billion, seven hundred sixty-four million, three hundred sixty-five thousand, two hundred twenty-one".