261987436 has 24 divisors (see below), whose sum is σ = 467112464. Its totient is φ = 128537280.

The previous prime is 261987413. The next prime is 261987461. The reversal of 261987436 is 634789162.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 126586 + ... + 128638.

Almost surely, 2^261987436 is an apocalyptic number.

It is an amenable number.

261987436 is a deficient number, since it is larger than the sum of its proper divisors (205125028).

261987436 is a wasteful number, since it uses less digits than its factorization.

261987436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2641 (or 2639 counting only the distinct ones).

The product of its digits is 435456, while the sum is 46.

The square root of 261987436 is about 16186.0259483296. The cubic root of 261987436 is about 639.8725625168.

The spelling of 261987436 in words is "two hundred sixty-one million, nine hundred eighty-seven thousand, four hundred thirty-six".