261501263 has 4 divisors (see below), whose sum is σ = 261537600. Its totient is φ = 261464928.

The previous prime is 261501223. The next prime is 261501269. The reversal of 261501263 is 362105162.

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

It is a cyclic number.

It is not a de Polignac number, because 261501263 - 2¹⁴ = 261484879 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261501269) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3338 + ... + 23111.

It is an arithmetic number, because the mean of its divisors is an integer number (65384400).

Almost surely, 2^261501263 is an apocalyptic number.

261501263 is a deficient number, since it is larger than the sum of its proper divisors (36337).

261501263 is an equidigital number, since it uses as much as digits as its factorization.

261501263 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36336.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 261501263 is about 16171.0006802300. Note that the first 3 decimals coincide. The cubic root of 261501263 is about 639.4765112188.

The spelling of 261501263 in words is "two hundred sixty-one million, five hundred one thousand, two hundred sixty-three".