265138649 has 2 divisors, whose sum is σ = 265138650. Its totient is φ = 265138648.

The previous prime is 265138639. The next prime is 265138651. The reversal of 265138649 is 946831562.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 150798400 + 114340249 = 12280^2 + 10693^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-265138649 is a prime.

Together with 265138651, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (265138639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 132569324 + 132569325.

It is an arithmetic number, because the mean of its divisors is an integer number (132569325).

Almost surely, 2^265138649 is an apocalyptic number.

It is an amenable number.

265138649 is a deficient number, since it is larger than the sum of its proper divisors (1).

265138649 is an equidigital number, since it uses as much as digits as its factorization.

265138649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 311040, while the sum is 44.

The square root of 265138649 is about 16283.0786094031. The cubic root of 265138649 is about 642.4278300139.

The spelling of 265138649 in words is "two hundred sixty-five million, one hundred thirty-eight thousand, six hundred forty-nine".