645576601 has 4 divisors (see below), whose sum is σ = 645627492. Its totient is φ = 645525712.

The previous prime is 645576559. The next prime is 645576619. The reversal of 645576601 is 106675546.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 552955225 + 92621376 = 23515^2 + 9624^2 .

It is a cyclic number.

It is not a de Polignac number, because 645576601 - 2⁷ = 645576473 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645576641) 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, 10671 + ... + 37483.

It is an arithmetic number, because the mean of its divisors is an integer number (161406873).

Almost surely, 2^645576601 is an apocalyptic number.

It is an amenable number.

645576601 is a deficient number, since it is larger than the sum of its proper divisors (50891).

645576601 is a wasteful number, since it uses less digits than its factorization.

645576601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50890.

The product of its (nonzero) digits is 151200, while the sum is 40.

The square root of 645576601 is about 25408.1994836313. The cubic root of 645576601 is about 864.2696457936.

The spelling of 645576601 in words is "six hundred forty-five million, five hundred seventy-six thousand, six hundred one".