261747163 has 4 divisors (see below), whose sum is σ = 261899248. Its totient is φ = 261595080.

The previous prime is 261747137. The next prime is 261747169. The reversal of 261747163 is 361747162.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261747163 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261747169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 73431 + ... + 76912.

It is an arithmetic number, because the mean of its divisors is an integer number (65474812).

Almost surely, 2^261747163 is an apocalyptic number.

261747163 is a deficient number, since it is larger than the sum of its proper divisors (152085).

261747163 is a wasteful number, since it uses less digits than its factorization.

261747163 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152084.

The product of its digits is 42336, while the sum is 37.

The square root of 261747163 is about 16178.6020100626. The cubic root of 261747163 is about 639.6768901251.

Subtracting 261747163 from its reverse (361747162), we obtain a palindrome (99999999).

The spelling of 261747163 in words is "two hundred sixty-one million, seven hundred forty-seven thousand, one hundred sixty-three".