263640905 has 8 divisors (see below), whose sum is σ = 345129984. Its totient is φ = 191738800.

The previous prime is 263640899. The next prime is 263640917. The reversal of 263640905 is 509046362.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 263640905 - 2⁸ = 263640649 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2396681 + ... + 2396790.

It is an arithmetic number, because the mean of its divisors is an integer number (43141248).

Almost surely, 2^263640905 is an apocalyptic number.

It is an amenable number.

263640905 is a deficient number, since it is larger than the sum of its proper divisors (81489079).

263640905 is a wasteful number, since it uses less digits than its factorization.

263640905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4793487.

The product of its (nonzero) digits is 38880, while the sum is 35.

The square root of 263640905 is about 16237.0226642695. The cubic root of 263640905 is about 641.2158730272.

The spelling of 263640905 in words is "two hundred sixty-three million, six hundred forty thousand, nine hundred five".