64821668 has 12 divisors (see below), whose sum is σ = 114015132. Its totient is φ = 32245920.

The previous prime is 64821667. The next prime is 64821719. The reversal of 64821668 is 86612846.

It can be written as a sum of positive squares in 2 ways, for example, as 37552384 + 27269284 = 6128^2 + 5222^2 .

It is not an unprimeable number, because it can be changed into a prime (64821667) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40343 + ... + 41918.

It is an arithmetic number, because the mean of its divisors is an integer number (9501261).

Almost surely, 2^64821668 is an apocalyptic number.

It is an amenable number.

64821668 is a deficient number, since it is larger than the sum of its proper divisors (49193464).

64821668 is a wasteful number, since it uses less digits than its factorization.

64821668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82462 (or 82460 counting only the distinct ones).

The product of its digits is 110592, while the sum is 41.

The square root of 64821668 is about 8051.1904709801. The cubic root of 64821668 is about 401.7045344218.

The spelling of 64821668 in words is "sixty-four million, eight hundred twenty-one thousand, six hundred sixty-eight".