64520273 has 4 divisors (see below), whose sum is σ = 66745140. Its totient is φ = 62295408.

The previous prime is 64520231. The next prime is 64520293. The reversal of 64520273 is 37202546.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 51437584 + 13082689 = 7172^2 + 3617^2 .

It is a cyclic number.

It is not a de Polignac number, because 64520273 - 2⁸ = 64520017 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29), and also a Moran number because the ratio is a prime number: 2224837 = 64520273 / (6 + 4 + 5 + 2 + 0 + 2 + 7 + 3).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64520293) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1112390 + ... + 1112447.

It is an arithmetic number, because the mean of its divisors is an integer number (16686285).

Almost surely, 2^64520273 is an apocalyptic number.

It is an amenable number.

64520273 is a deficient number, since it is larger than the sum of its proper divisors (2224867).

64520273 is a wasteful number, since it uses less digits than its factorization.

64520273 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2224866.

The product of its (nonzero) digits is 10080, while the sum is 29.

The square root of 64520273 is about 8032.4512447945. The cubic root of 64520273 is about 401.0809781673.

The spelling of 64520273 in words is "sixty-four million, five hundred twenty thousand, two hundred seventy-three".