261849 has 16 divisors (see below), whose sum is σ = 411008. Its totient is φ = 145152.

The previous prime is 261847. The next prime is 261881. The reversal of 261849 is 948162.

261849 = 112² + 113² + ... + 129².

It is not a de Polignac number, because 261849 - 2¹ = 261847 is a prime.

It is a Duffinian number.

Its product of digits (3456) is a multiple of the sum of its prime divisors (384).

261849 is a lucky number.

It is a nialpdrome in base 8.

It is not an unprimeable number, because it can be changed into a prime (261847) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 609 + ... + 945.

It is an arithmetic number, because the mean of its divisors is an integer number (25688).

261849 is a Friedman number, since it can be written as 8^6-291-4, using all its digits and the basic arithmetic operations.

2²⁶¹⁸⁴⁹ is an apocalyptic number.

It is an amenable number.

261849 is a deficient number, since it is larger than the sum of its proper divisors (149159).

261849 is a wasteful number, since it uses less digits than its factorization.

261849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 384.

The product of its digits is 3456, while the sum is 30.

The square root of 261849 is about 511.7118329685. The cubic root of 261849 is about 63.9759838275.

The spelling of 261849 in words is "two hundred sixty-one thousand, eight hundred forty-nine".