263478857 has 4 divisors (see below), whose sum is σ = 263514900. Its totient is φ = 263442816.

The previous prime is 263478829. The next prime is 263478877. The reversal of 263478857 is 758874362.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 758874362 = 2 ⋅379437181.

It can be written as a sum of positive squares in 2 ways, for example, as 74718736 + 188760121 = 8644^2 + 13739^2 .

It is a cyclic number.

It is not a de Polignac number, because 263478857 - 2¹⁰ = 263477833 is a prime.

It is a super-2 number, since 2×263478857² = 138842216172052898, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (263478877) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2732 + ... + 23117.

It is an arithmetic number, because the mean of its divisors is an integer number (65878725).

Almost surely, 2^263478857 is an apocalyptic number.

It is an amenable number.

263478857 is a deficient number, since it is larger than the sum of its proper divisors (36043).

263478857 is a wasteful number, since it uses less digits than its factorization.

263478857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36042.

The product of its digits is 2257920, while the sum is 50.

The square root of 263478857 is about 16232.0318198308. The cubic root of 263478857 is about 641.0844707496.

The spelling of 263478857 in words is "two hundred sixty-three million, four hundred seventy-eight thousand, eight hundred fifty-seven".