265978 has 4 divisors (see below), whose sum is σ = 398970. Its totient is φ = 132988.

The previous prime is 265961. The next prime is 265987. The reversal of 265978 is 879562.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 879562 = 2 ⋅439781.

It can be written as a sum of positive squares in only one way, i.e., 263169 + 2809 = 513^2 + 53^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66493 + ... + 66496.

2²⁶⁵⁹⁷⁸ is an apocalyptic number.

265978 is a deficient number, since it is larger than the sum of its proper divisors (132992).

265978 is a wasteful number, since it uses less digits than its factorization.

265978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132991.

The product of its digits is 30240, while the sum is 37.

The square root of 265978 is about 515.7305498029. The cubic root of 265978 is about 64.3105028448.

The spelling of 265978 in words is "two hundred sixty-five thousand, nine hundred seventy-eight".