64789821 has 16 divisors (see below), whose sum is σ = 96566400. Its totient is φ = 42931584.

The previous prime is 64789817. The next prime is 64789831. The reversal of 64789821 is 12898746.

It is not a de Polignac number, because 64789821 - 2² = 64789817 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64789801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2676 + ... + 11693.

It is an arithmetic number, because the mean of its divisors is an integer number (6035400).

Almost surely, 2^64789821 is an apocalyptic number.

It is an amenable number.

64789821 is a deficient number, since it is larger than the sum of its proper divisors (31776579).

64789821 is a wasteful number, since it uses less digits than its factorization.

64789821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14545 (or 14539 counting only the distinct ones).

The product of its digits is 193536, while the sum is 45.

The square root of 64789821 is about 8049.2124459477. The cubic root of 64789821 is about 401.6387375961.

The spelling of 64789821 in words is "sixty-four million, seven hundred eighty-nine thousand, eight hundred twenty-one".