1861243605 has 96 divisors (see below), whose sum is σ = 3710843136. Its totient is φ = 855816192.

The previous prime is 1861243603. The next prime is 1861243633. The reversal of 1861243605 is 5063421681.

It is a happy number.

1861243605 is a `hidden beast` number, since 1 + 8 + 6 + 1 + 2 + 43 + 605 = 666.

It is not a de Polignac number, because 1861243605 - 2¹ = 1861243603 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1861243605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1861243603) by changing a digit.

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 95 ways as a sum of consecutive naturals, for example, 576957 + ... + 580173.

It is an arithmetic number, because the mean of its divisors is an integer number (38654616).

Almost surely, 2^1861243605 is an apocalyptic number.

1861243605 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1861243605 is a deficient number, since it is larger than the sum of its proper divisors (1849599531).

1861243605 is a wasteful number, since it uses less digits than its factorization.

1861243605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3307 (or 3304 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 1861243605 is about 43142.1325968015. The cubic root of 1861243605 is about 1230.0829708059.

The spelling of 1861243605 in words is "one billion, eight hundred sixty-one million, two hundred forty-three thousand, six hundred five".