64345521 has 4 divisors (see below), whose sum is σ = 85794032. Its totient is φ = 42897012.

The previous prime is 64345517. The next prime is 64345531. The reversal of 64345521 is 12554346.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 64345521 - 2² = 64345517 is a prime.

It is a super-2 number, since 2×64345521² = 8280692145522882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64345531) 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, 10724251 + ... + 10724256.

It is an arithmetic number, because the mean of its divisors is an integer number (21448508).

Almost surely, 2^64345521 is an apocalyptic number.

It is an amenable number.

64345521 is a deficient number, since it is larger than the sum of its proper divisors (21448511).

64345521 is a wasteful number, since it uses less digits than its factorization.

64345521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21448510.

The product of its digits is 14400, while the sum is 30.

The square root of 64345521 is about 8021.5659942433. The cubic root of 64345521 is about 400.7185438805.

Adding to 64345521 its reverse (12554346), we get a palindrome (76899867).

It can be divided in two parts, 643 and 45521, that added together give a palindrome (46164).

The spelling of 64345521 in words is "sixty-four million, three hundred forty-five thousand, five hundred twenty-one".