645406601 has 4 divisors (see below), whose sum is σ = 737607552. Its totient is φ = 553205652.

The previous prime is 645406583. The next prime is 645406603. The reversal of 645406601 is 106604546.

645406601 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 a cyclic number.

It is not a de Polignac number, because 645406601 - 2¹⁴ = 645390217 is a prime.

It is a super-2 number, since 2×645406601² = 833099361228746402, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645406603) 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, 46100465 + ... + 46100478.

It is an arithmetic number, because the mean of its divisors is an integer number (184401888).

Almost surely, 2^645406601 is an apocalyptic number.

It is an amenable number.

645406601 is a deficient number, since it is larger than the sum of its proper divisors (92200951).

645406601 is an equidigital number, since it uses as much as digits as its factorization.

645406601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92200950.

The product of its (nonzero) digits is 17280, while the sum is 32.

The square root of 645406601 is about 25404.8538866099. The cubic root of 645406601 is about 864.1937762851.

The spelling of 645406601 in words is "six hundred forty-five million, four hundred six thousand, six hundred one".