261861449 has 4 divisors (see below), whose sum is σ = 261930900. Its totient is φ = 261792000.

The previous prime is 261861437. The next prime is 261861451. The reversal of 261861449 is 944168162.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 75811849 + 186049600 = 8707^2 + 13640^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261861449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261861409) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28724 + ... + 36725.

It is an arithmetic number, because the mean of its divisors is an integer number (65482725).

Almost surely, 2^261861449 is an apocalyptic number.

It is an amenable number.

261861449 is a deficient number, since it is larger than the sum of its proper divisors (69451).

261861449 is an equidigital number, since it uses as much as digits as its factorization.

261861449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69450.

The product of its digits is 82944, while the sum is 41.

The square root of 261861449 is about 16182.1336355871. The cubic root of 261861449 is about 639.7699767445.

The spelling of 261861449 in words is "two hundred sixty-one million, eight hundred sixty-one thousand, four hundred forty-nine".