263960991 has 48 divisors (see below), whose sum is σ = 458772480. Its totient is φ = 149551920.

The previous prime is 263960981. The next prime is 263961011. The reversal of 263960991 is 199069362.

It is a happy number.

263960991 is a `hidden beast` number, since 2 + 6 + 39 + 609 + 9 + 1 = 666.

It is not a de Polignac number, because 263960991 - 2⁶ = 263960927 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (263960981) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 167236 + ... + 168806.

It is an arithmetic number, because the mean of its divisors is an integer number (9557760).

Almost surely, 2^263960991 is an apocalyptic number.

263960991 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

263960991 is a deficient number, since it is larger than the sum of its proper divisors (194811489).

263960991 is a wasteful number, since it uses less digits than its factorization.

263960991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1721 (or 1708 counting only the distinct ones).

The product of its (nonzero) digits is 157464, while the sum is 45.

The square root of 263960991 is about 16246.8763459319. The cubic root of 263960991 is about 641.4752677997.

The spelling of 263960991 in words is "two hundred sixty-three million, nine hundred sixty thousand, nine hundred ninety-one".