261155436 has 12 divisors (see below), whose sum is σ = 609362712. Its totient is φ = 87051808.

The previous prime is 261155423. The next prime is 261155449. The reversal of 261155436 is 634551162.

It is an interprime number because it is at equal distance from previous prime (261155423) and next prime (261155449).

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 261155397 and 261155406.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10881465 + ... + 10881488.

It is an arithmetic number, because the mean of its divisors is an integer number (50780226).

Almost surely, 2^261155436 is an apocalyptic number.

It is an amenable number.

261155436 is an abundant number, since it is smaller than the sum of its proper divisors (348207276).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261155436 is a wasteful number, since it uses less digits than its factorization.

261155436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21762960 (or 21762958 counting only the distinct ones).

The product of its digits is 21600, while the sum is 33.

The square root of 261155436 is about 16160.3043288176. The cubic root of 261155436 is about 639.1944911631.

The spelling of 261155436 in words is "two hundred sixty-one million, one hundred fifty-five thousand, four hundred thirty-six".