261871424 has 14 divisors (see below), whose sum is σ = 519651234. Its totient is φ = 130935680.

The previous prime is 261871403. The next prime is 261871429. The reversal of 261871424 is 424178162.

It can be written as a sum of positive squares in only one way, i.e., 168169024 + 93702400 = 12968^2 + 9680^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261871429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2045807 + ... + 2045934.

Almost surely, 2^261871424 is an apocalyptic number.

It is an amenable number.

261871424 is a deficient number, since it is larger than the sum of its proper divisors (257779810).

261871424 is an equidigital number, since it uses as much as digits as its factorization.

261871424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4091753 (or 4091743 counting only the distinct ones).

The product of its digits is 21504, while the sum is 35.

The square root of 261871424 is about 16182.4418429358. The cubic root of 261871424 is about 639.7781001554.

The spelling of 261871424 in words is "two hundred sixty-one million, eight hundred seventy-one thousand, four hundred twenty-four".