64043989 has 2 divisors, whose sum is σ = 64043990. Its totient is φ = 64043988.

The previous prime is 64043951. The next prime is 64044017. The reversal of 64043989 is 98934046.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60684100 + 3359889 = 7790^2 + 1833^2 .

It is a cyclic number.

It is not a de Polignac number, because 64043989 - 2²³ = 55655381 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64043689) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32021994 + 32021995.

It is an arithmetic number, because the mean of its divisors is an integer number (32021995).

Almost surely, 2^64043989 is an apocalyptic number.

It is an amenable number.

64043989 is a deficient number, since it is larger than the sum of its proper divisors (1).

64043989 is an equidigital number, since it uses as much as digits as its factorization.

64043989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 186624, while the sum is 43.

The square root of 64043989 is about 8002.7488402423. The cubic root of 64043989 is about 400.0916227616.

The spelling of 64043989 in words is "sixty-four million, forty-three thousand, nine hundred eighty-nine".