61643811 has 12 divisors (see below), whose sum is σ = 84155208. Its totient is φ = 40136544.

The previous prime is 61643797. The next prime is 61643831. The reversal of 61643811 is 11834616.

61643811 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 61643811 - 2¹¹ = 61641763 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61643831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10 + ... + 11103.

It is an arithmetic number, because the mean of its divisors is an integer number (7012934).

Almost surely, 2^61643811 is an apocalyptic number.

61643811 is a deficient number, since it is larger than the sum of its proper divisors (22511397).

61643811 is a wasteful number, since it uses less digits than its factorization.

61643811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11202 (or 11159 counting only the distinct ones).

The product of its digits is 3456, while the sum is 30.

The square root of 61643811 is about 7851.3572711984. The cubic root of 61643811 is about 395.0297707626.

The spelling of 61643811 in words is "sixty-one million, six hundred forty-three thousand, eight hundred eleven".