64609818 has 64 divisors (see below), whose sum is σ = 161317632. Its totient is φ = 16796160.

The previous prime is 64609813. The next prime is 64609837. The reversal of 64609818 is 81890646.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 64609818.

It is not an unprimeable number, because it can be changed into a prime (64609813) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 39048 + ... + 40668.

It is an arithmetic number, because the mean of its divisors is an integer number (2520588).

Almost surely, 2^64609818 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64609818, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80658816).

64609818 is an abundant number, since it is smaller than the sum of its proper divisors (96707814).

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

64609818 is a wasteful number, since it uses less digits than its factorization.

64609818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1719.

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

The square root of 64609818 is about 8038.0232644600. The cubic root of 64609818 is about 401.2664402577.

The spelling of 64609818 in words is "sixty-four million, six hundred nine thousand, eight hundred eighteen".