64043921 has 2 divisors, whose sum is σ = 64043922. Its totient is φ = 64043920.

The previous prime is 64043897. The next prime is 64043951. The reversal of 64043921 is 12934046.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54184321 + 9859600 = 7361^2 + 3140^2 .

It is a cyclic number.

It is not a de Polignac number, because 64043921 - 2⁶ = 64043857 is a prime.

It is not a weakly prime, because it can be changed into another prime (64043951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32021960 + 32021961.

It is an arithmetic number, because the mean of its divisors is an integer number (32021961).

Almost surely, 2^64043921 is an apocalyptic number.

It is an amenable number.

64043921 is a deficient number, since it is larger than the sum of its proper divisors (1).

64043921 is an equidigital number, since it uses as much as digits as its factorization.

64043921 is an evil number, because the sum of its binary digits is even.

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

The square root of 64043921 is about 8002.7445917010. The cubic root of 64043921 is about 400.0914811597.

Adding to 64043921 its reverse (12934046), we get a palindrome (76977967).

The spelling of 64043921 in words is "sixty-four million, forty-three thousand, nine hundred twenty-one".