261144135 has 32 divisors (see below), whose sum is σ = 530580480. Its totient is φ = 119379744.

The previous prime is 261144133. The next prime is 261144137. The reversal of 261144135 is 531441162.

It is a happy number.

261144135 is a `hidden beast` number, since 2 + 611 + 4 + 41 + 3 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (261144133) and next prime (261144137).

It is not a de Polignac number, because 261144135 - 2¹ = 261144133 is a prime.

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

It is a junction number, because it is equal to n+sod(n) for n = 261144099 and 261144108.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261144133) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 137227 + ... + 139116.

It is an arithmetic number, because the mean of its divisors is an integer number (16580640).

Almost surely, 2^261144135 is an apocalyptic number.

261144135 is an abundant number, since it is smaller than the sum of its proper divisors (269436345).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261144135 is a wasteful number, since it uses less digits than its factorization.

261144135 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276364 (or 276358 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 261144135 is about 16159.9546719661. The cubic root of 261144135 is about 639.1852710587.

Adding to 261144135 its reverse (531441162), we get a palindrome (792585297).

The spelling of 261144135 in words is "two hundred sixty-one million, one hundred forty-four thousand, one hundred thirty-five".