64821243 has 4 divisors (see below), whose sum is σ = 86428328. Its totient is φ = 43214160.

The previous prime is 64821233. The next prime is 64821271. The reversal of 64821243 is 34212846.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 64821243 - 2¹² = 64817147 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 64821243.

It is not an unprimeable number, because it can be changed into a prime (64821233) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10803538 + ... + 10803543.

It is an arithmetic number, because the mean of its divisors is an integer number (21607082).

Almost surely, 2^64821243 is an apocalyptic number.

64821243 is a deficient number, since it is larger than the sum of its proper divisors (21607085).

64821243 is a wasteful number, since it uses less digits than its factorization.

64821243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21607084.

The product of its digits is 9216, while the sum is 30.

The square root of 64821243 is about 8051.1640773245. The cubic root of 64821243 is about 401.7036565014.

The spelling of 64821243 in words is "sixty-four million, eight hundred twenty-one thousand, two hundred forty-three".