261645436 has 48 divisors (see below), whose sum is σ = 534915360. Its totient is φ = 110868480.

The previous prime is 261645431. The next prime is 261645443. The reversal of 261645436 is 634546162.

It is a junction number, because it is equal to n+sod(n) for n = 261645395 and 261645404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261645431) 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, 32635 + ... + 39853.

It is an arithmetic number, because the mean of its divisors is an integer number (11144070).

Almost surely, 2^261645436 is an apocalyptic number.

261645436 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

261645436 is an abundant number, since it is smaller than the sum of its proper divisors (273269924).

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

261645436 is a wasteful number, since it uses less digits than its factorization.

261645436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7294 (or 7292 counting only the distinct ones).

The product of its digits is 103680, while the sum is 37.

The square root of 261645436 is about 16175.4578296875. The cubic root of 261645436 is about 639.5940100891.

The spelling of 261645436 in words is "two hundred sixty-one million, six hundred forty-five thousand, four hundred thirty-six".