261771836 has 12 divisors (see below), whose sum is σ = 460749912. Its totient is φ = 130129008.

The previous prime is 261771833. The next prime is 261771841. The reversal of 261771836 is 638177162.

It is a junction number, because it is equal to n+sod(n) for n = 261771793 and 261771802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261771833) 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, 188450 + ... + 189833.

It is an arithmetic number, because the mean of its divisors is an integer number (38395826).

Almost surely, 2^261771836 is an apocalyptic number.

It is an amenable number.

261771836 is a deficient number, since it is larger than the sum of its proper divisors (198978076).

261771836 is a wasteful number, since it uses less digits than its factorization.

261771836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 378460 (or 378458 counting only the distinct ones).

The product of its digits is 84672, while the sum is 41.

The square root of 261771836 is about 16179.3645116241. The cubic root of 261771836 is about 639.6969887219.

The spelling of 261771836 in words is "two hundred sixty-one million, seven hundred seventy-one thousand, eight hundred thirty-six".