261481757 has 4 divisors (see below), whose sum is σ = 261514176. Its totient is φ = 261449340.

The previous prime is 261481747. The next prime is 261481763. The reversal of 261481757 is 757184162.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 261481757 - 2⁴ = 261481741 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 (261481747) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6428 + ... + 23754.

It is an arithmetic number, because the mean of its divisors is an integer number (65378544).

Almost surely, 2^261481757 is an apocalyptic number.

It is an amenable number.

261481757 is a deficient number, since it is larger than the sum of its proper divisors (32419).

261481757 is a wasteful number, since it uses less digits than its factorization.

261481757 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32418.

The product of its digits is 94080, while the sum is 41.

The square root of 261481757 is about 16170.3975523176. The cubic root of 261481757 is about 639.4606107998.

The spelling of 261481757 in words is "two hundred sixty-one million, four hundred eighty-one thousand, seven hundred fifty-seven".