1665264749 has 2 divisors, whose sum is σ = 1665264750. Its totient is φ = 1665264748.

The previous prime is 1665264721. The next prime is 1665264751. The reversal of 1665264749 is 9474625661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 851589124 + 813675625 = 29182^2 + 28525^2 .

It is an emirp because it is prime and its reverse (9474625661) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1665264749 is a prime.

Together with 1665264751, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 1665264697 and 1665264706.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1665264449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 832632374 + 832632375.

It is an arithmetic number, because the mean of its divisors is an integer number (832632375).

Almost surely, 2^1665264749 is an apocalyptic number.

It is an amenable number.

1665264749 is a deficient number, since it is larger than the sum of its proper divisors (1).

1665264749 is an equidigital number, since it uses as much as digits as its factorization.

1665264749 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2177280, while the sum is 50.

The square root of 1665264749 is about 40807.6555195223. The cubic root of 1665264749 is about 1185.2985768073.

The spelling of 1665264749 in words is "one billion, six hundred sixty-five million, two hundred sixty-four thousand, seven hundred forty-nine".