64943021 has 16 divisors (see below), whose sum is σ = 76991040. Its totient is φ = 54001920.

The previous prime is 64943017. The next prime is 64943023. The reversal of 64943021 is 12034946.

It is a cyclic number.

It is not a de Polignac number, because 64943021 - 2² = 64943017 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64943023) 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 15 ways as a sum of consecutive naturals, for example, 14150 + ... + 18168.

It is an arithmetic number, because the mean of its divisors is an integer number (4811940).

Almost surely, 2^64943021 is an apocalyptic number.

It is an amenable number.

64943021 is a deficient number, since it is larger than the sum of its proper divisors (12048019).

64943021 is a wasteful number, since it uses less digits than its factorization.

64943021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4156.

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 64943021 is about 8058.7232859802. The cubic root of 64943021 is about 401.9550559062.

Adding to 64943021 its reverse (12034946), we get a palindrome (76977967).

The spelling of 64943021 in words is "sixty-four million, nine hundred forty-three thousand, twenty-one".