263904985 has 4 divisors (see below), whose sum is σ = 316685988. Its totient is φ = 211123984.

The previous prime is 263904973. The next prime is 263904997. The reversal of 263904985 is 589409362.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (263904973) and next prime (263904997).

It can be written as a sum of positive squares in 2 ways, for example, as 190357209 + 73547776 = 13797^2 + 8576^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-263904985 is a prime.

It is a super-2 number, since 2×263904985² = 139291682215700450, which contains 22 as substring.

It is a Duffinian number.

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, 26390494 + ... + 26390503.

It is an arithmetic number, because the mean of its divisors is an integer number (79171497).

Almost surely, 2^263904985 is an apocalyptic number.

It is an amenable number.

263904985 is a deficient number, since it is larger than the sum of its proper divisors (52781003).

263904985 is an equidigital number, since it uses as much as digits as its factorization.

263904985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52781002.

The product of its (nonzero) digits is 466560, while the sum is 46.

The square root of 263904985 is about 16245.1526616403. The cubic root of 263904985 is about 641.4298961901.

It can be divided in two parts, 26390 and 4985, that added together give a triangular number (31375 = T₂₅₀).

The spelling of 263904985 in words is "two hundred sixty-three million, nine hundred four thousand, nine hundred eighty-five".