64390312 has 48 divisors (see below), whose sum is σ = 141187860. Its totient is φ = 27449856.

The previous prime is 64390309. The next prime is 64390327. The reversal of 64390312 is 21309346.

It can be written as a sum of positive squares in 2 ways, for example, as 63457156 + 933156 = 7966^2 + 966^2 .

It is a super-2 number, since 2×64390312² = 8292224558914688, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 108288 + ... + 108880.

Almost surely, 2^64390312 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64390312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (70593930).

64390312 is an abundant number, since it is smaller than the sum of its proper divisors (76797548).

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

64390312 is a wasteful number, since it uses less digits than its factorization.

64390312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 890 (or 879 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 28.

The square root of 64390312 is about 8024.3574197564. The cubic root of 64390312 is about 400.8115025457.

Adding to 64390312 its reverse (21309346), we get a palindrome (85699658).

The spelling of 64390312 in words is "sixty-four million, three hundred ninety thousand, three hundred twelve".