61999864 has 16 divisors (see below), whose sum is σ = 119392200. Its totient is φ = 30161952.

The previous prime is 61999859. The next prime is 61999897. The reversal of 61999864 is 46899916.

61999864 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

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, 104434 + ... + 105025.

Almost surely, 2^61999864 is an apocalyptic number.

It is an amenable number.

61999864 is a deficient number, since it is larger than the sum of its proper divisors (57392336).

61999864 is a wasteful number, since it uses less digits than its factorization.

61999864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209502 (or 209498 counting only the distinct ones).

The product of its digits is 839808, while the sum is 52.

The square root of 61999864 is about 7873.9992379984. Note that the first 3 decimals coincide. The cubic root of 61999864 is about 395.7888715736.

Adding to 61999864 its sum of digits (52), we get a palindrome (61999916).

The spelling of 61999864 in words is "sixty-one million, nine hundred ninety-nine thousand, eight hundred sixty-four".