265985381 has 2 divisors, whose sum is σ = 265985382. Its totient is φ = 265985380.

The previous prime is 265985359. The next prime is 265985411. The reversal of 265985381 is 183589562.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 213422881 + 52562500 = 14609^2 + 7250^2 .

It is a cyclic number.

It is not a de Polignac number, because 265985381 - 2¹⁰ = 265984357 is a prime.

It is a super-2 number, since 2×265985381² = 141496445811430322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (265988381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 132992690 + 132992691.

It is an arithmetic number, because the mean of its divisors is an integer number (132992691).

Almost surely, 2^265985381 is an apocalyptic number.

It is an amenable number.

265985381 is a deficient number, since it is larger than the sum of its proper divisors (1).

265985381 is an equidigital number, since it uses as much as digits as its factorization.

265985381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 518400, while the sum is 47.

The square root of 265985381 is about 16309.0582499420. The cubic root of 265985381 is about 643.1109772033.

The spelling of 265985381 in words is "two hundred sixty-five million, nine hundred eighty-five thousand, three hundred eighty-one".