261387 has 20 divisors (see below), whose sum is σ = 447216. Its totient is φ = 149040.

The previous prime is 261379. The next prime is 261389. The reversal of 261387 is 783162.

It is not a de Polignac number, because 261387 - 2³ = 261379 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

261387 is a Rhonda number in base 15.

261387 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 261387.

It is not an unprimeable number, because it can be changed into a prime (261389) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 337 + ... + 797.

2²⁶¹³⁸⁷ is an apocalyptic number.

261387 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

261387 is a deficient number, since it is larger than the sum of its proper divisors (185829).

261387 is an equidigital number, since it uses as much as digits as its factorization.

261387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 480 (or 471 counting only the distinct ones).

The product of its digits is 2016, while the sum is 27.

The square root of 261387 is about 511.2602077221. The cubic root of 261387 is about 63.9383357877.

The spelling of 261387 in words is "two hundred sixty-one thousand, three hundred eighty-seven".