261786361 has 8 divisors (see below), whose sum is σ = 263894400. Its totient is φ = 259685088.

The previous prime is 261786337. The next prime is 261786367. The reversal of 261786361 is 163687162.

It is a happy number.

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 261786361 - 2¹³ = 261778169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261786367) 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 7 ways as a sum of consecutive naturals, for example, 98725 + ... + 101341.

It is an arithmetic number, because the mean of its divisors is an integer number (32986800).

Almost surely, 2^261786361 is an apocalyptic number.

It is an amenable number.

261786361 is a deficient number, since it is larger than the sum of its proper divisors (2108039).

261786361 is a wasteful number, since it uses less digits than its factorization.

261786361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3383.

The product of its digits is 72576, while the sum is 40.

The square root of 261786361 is about 16179.8133796407. The cubic root of 261786361 is about 639.7088201792.

It can be divided in two parts, 2617863 and 61, that added together give a square (2617924 = 1618²).

The spelling of 261786361 in words is "two hundred sixty-one million, seven hundred eighty-six thousand, three hundred sixty-one".