64520073 has 6 divisors (see below), whose sum is σ = 93195674. Its totient is φ = 43013376.

The previous prime is 64520069. The next prime is 64520123. The reversal of 64520073 is 37002546.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 64448784 + 71289 = 8028^2 + 267^2 .

It is not a de Polignac number, because 64520073 - 2² = 64520069 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64520003) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3584440 + ... + 3584457.

Almost surely, 2^64520073 is an apocalyptic number.

It is an amenable number.

64520073 is a deficient number, since it is larger than the sum of its proper divisors (28675601).

64520073 is a wasteful number, since it uses less digits than its factorization.

64520073 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7168903 (or 7168900 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 27.

The square root of 64520073 is about 8032.4387952850. The cubic root of 64520073 is about 401.0805637431.

The spelling of 64520073 in words is "sixty-four million, five hundred twenty thousand, seventy-three".