261723287 has 8 divisors (see below), whose sum is σ = 302899200. Its totient is φ = 221494104.

The previous prime is 261723229. The next prime is 261723331. The reversal of 261723287 is 782327162.

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 261723287 - 2¹² = 261719191 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 261723287.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261723227) 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, 236087 + ... + 237192.

It is an arithmetic number, because the mean of its divisors is an integer number (37862400).

Almost surely, 2^261723287 is an apocalyptic number.

261723287 is a deficient number, since it is larger than the sum of its proper divisors (41175913).

261723287 is an equidigital number, since it uses as much as digits as its factorization.

261723287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 473365.

The product of its digits is 56448, while the sum is 38.

The square root of 261723287 is about 16177.8641050047. The cubic root of 261723287 is about 639.6574395611.

The spelling of 261723287 in words is "two hundred sixty-one million, seven hundred twenty-three thousand, two hundred eighty-seven".