261687751 has 8 divisors (see below), whose sum is σ = 282566480. Its totient is φ = 240916032.

The previous prime is 261687739. The next prime is 261687781. The reversal of 261687751 is 157786162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 261687751 - 2¹¹ = 261685703 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261687698 and 261687707.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261687781) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21630 + ... + 31483.

It is an arithmetic number, because the mean of its divisors is an integer number (35320810).

Almost surely, 2^261687751 is an apocalyptic number.

261687751 is a deficient number, since it is larger than the sum of its proper divisors (20878729).

261687751 is a wasteful number, since it uses less digits than its factorization.

261687751 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53505.

The product of its digits is 141120, while the sum is 43.

The square root of 261687751 is about 16176.7657768789. The cubic root of 261687751 is about 639.6284879969.

The spelling of 261687751 in words is "two hundred sixty-one million, six hundred eighty-seven thousand, seven hundred fifty-one".