64780073 has 2 divisors, whose sum is σ = 64780074. Its totient is φ = 64780072.

The previous prime is 64780061. The next prime is 64780091. The reversal of 64780073 is 37008746.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 47706649 + 17073424 = 6907^2 + 4132^2 .

It is a cyclic number.

It is not a de Polignac number, because 64780073 - 2²⁰ = 63731497 is a prime.

It is a zygodrome in base 3.

It is not a weakly prime, because it can be changed into another prime (64780003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32390036 + 32390037.

It is an arithmetic number, because the mean of its divisors is an integer number (32390037).

Almost surely, 2^64780073 is an apocalyptic number.

It is an amenable number.

64780073 is a deficient number, since it is larger than the sum of its proper divisors (1).

64780073 is an equidigital number, since it uses as much as digits as its factorization.

64780073 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28224, while the sum is 35.

The square root of 64780073 is about 8048.6068980911. The cubic root of 64780073 is about 401.6185936356.

The spelling of 64780073 in words is "sixty-four million, seven hundred eighty thousand, seventy-three".