61808643 has 32 divisors (see below), whose sum is σ = 99113280. Its totient is φ = 37843200.

The previous prime is 61808641. The next prime is 61808647. The reversal of 61808643 is 34680816.

It is a happy number.

61808643 is a `hidden beast` number, since 6 + 1 + 8 + 0 + 8 + 643 = 666.

It is not a de Polignac number, because 61808643 - 2¹ = 61808641 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 61808598 and 61808607.

It is not an unprimeable number, because it can be changed into a prime (61808641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 102543 + ... + 103143.

It is an arithmetic number, because the mean of its divisors is an integer number (3097290).

Almost surely, 2^61808643 is an apocalyptic number.

61808643 is a deficient number, since it is larger than the sum of its proper divisors (37304637).

61808643 is a wasteful number, since it uses less digits than its factorization.

61808643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 916 (or 910 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 61808643 is about 7861.8473020022. The cubic root of 61808643 is about 395.3815530181.

The spelling of 61808643 in words is "sixty-one million, eight hundred eight thousand, six hundred forty-three".