61809864 has 16 divisors (see below), whose sum is σ = 154524720. Its totient is φ = 20603280.

The previous prime is 61809863. The next prime is 61809889. The reversal of 61809864 is 46890816.

61809864 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (61809863) 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 3 ways as a sum of consecutive naturals, for example, 1287682 + ... + 1287729.

It is an arithmetic number, because the mean of its divisors is an integer number (9657795).

Almost surely, 2^61809864 is an apocalyptic number.

It is an amenable number.

61809864 is an abundant number, since it is smaller than the sum of its proper divisors (92714856).

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

61809864 is a wasteful number, since it uses less digits than its factorization.

61809864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2575420 (or 2575416 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 42.

The square root of 61809864 is about 7861.9249551239. The cubic root of 61809864 is about 395.3841565251.

The spelling of 61809864 in words is "sixty-one million, eight hundred nine thousand, eight hundred sixty-four".