263607561 has 16 divisors (see below), whose sum is σ = 446320000. Its totient is φ = 150632784.

The previous prime is 263607557. The next prime is 263607563. The reversal of 263607561 is 165706362.

It is not a de Polignac number, because 263607561 - 2² = 263607557 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (263607563) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 697186 + ... + 697563.

It is an arithmetic number, because the mean of its divisors is an integer number (27895000).

Almost surely, 2^263607561 is an apocalyptic number.

263607561 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

263607561 is a deficient number, since it is larger than the sum of its proper divisors (182712439).

263607561 is a wasteful number, since it uses less digits than its factorization.

263607561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1394765 (or 1394759 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 36.

The square root of 263607561 is about 16235.9958425715. The cubic root of 263607561 is about 641.1888392816.

The spelling of 263607561 in words is "two hundred sixty-three million, six hundred seven thousand, five hundred sixty-one".