261712409 has 16 divisors (see below), whose sum is σ = 301916160. Its totient is φ = 222225360.

The previous prime is 261712393. The next prime is 261712453. The reversal of 261712409 is 904217162.

It is a happy number.

It is not a de Polignac number, because 261712409 - 2⁴ = 261712393 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261712459) 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, 520052 + ... + 520554.

It is an arithmetic number, because the mean of its divisors is an integer number (18869760).

Almost surely, 2^261712409 is an apocalyptic number.

It is an amenable number.

261712409 is a deficient number, since it is larger than the sum of its proper divisors (40203751).

261712409 is a wasteful number, since it uses less digits than its factorization.

261712409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1060.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 261712409 is about 16177.5279013822. The cubic root of 261712409 is about 639.6485774150.

The spelling of 261712409 in words is "two hundred sixty-one million, seven hundred twelve thousand, four hundred nine".