64438686 has 96 divisors (see below), whose sum is σ = 162328320. Its totient is φ = 18903456.

The previous prime is 64438637. The next prime is 64438711. The reversal of 64438686 is 68683446.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 209745 + ... + 210051.

It is an arithmetic number, because the mean of its divisors is an integer number (1690920).

Almost surely, 2^64438686 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64438686, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81164160).

64438686 is an abundant number, since it is smaller than the sum of its proper divisors (97889634).

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

64438686 is a wasteful number, since it uses less digits than its factorization.

64438686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 367 (or 348 counting only the distinct ones).

The product of its digits is 663552, while the sum is 45.

The square root of 64438686 is about 8027.3710515959. The cubic root of 64438686 is about 400.9118489160.

It can be divided in two parts, 6443 and 8686, that added together give a square (15129 = 123²).

The spelling of 64438686 in words is "sixty-four million, four hundred thirty-eight thousand, six hundred eighty-six".