263790640 has 20 divisors (see below), whose sum is σ = 613313424. Its totient is φ = 105516224.

The previous prime is 263790617. The next prime is 263790691. The reversal of 263790640 is 46097362.

It is a tau number, because it is divible by the number of its divisors (20).

It is a self number, because there is not a number n which added to its sum of digits gives 263790640.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1648612 + ... + 1648771.

Almost surely, 2^263790640 is an apocalyptic number.

263790640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

263790640 is an abundant number, since it is smaller than the sum of its proper divisors (349522784).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

263790640 is a wasteful number, since it uses less digits than its factorization.

263790640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3297396 (or 3297390 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 37.

The square root of 263790640 is about 16241.6329228314. The cubic root of 263790640 is about 641.3372430244.

The spelling of 263790640 in words is "two hundred sixty-three million, seven hundred ninety thousand, six hundred forty".