645402001 has 4 divisors (see below), whose sum is σ = 645498352. Its totient is φ = 645305652.

The previous prime is 645401987. The next prime is 645402031. The reversal of 645402001 is 100204546.

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 645402001 - 2⁵ = 645401969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645402031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37311 + ... + 51796.

It is an arithmetic number, because the mean of its divisors is an integer number (161374588).

Almost surely, 2^645402001 is an apocalyptic number.

It is an amenable number.

645402001 is a deficient number, since it is larger than the sum of its proper divisors (96351).

645402001 is an equidigital number, since it uses as much as digits as its factorization.

645402001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96350.

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 645402001 is about 25404.7633525684. The cubic root of 645402001 is about 864.1917231603.

Adding to 645402001 its reverse (100204546), we get a palindrome (745606547).

The spelling of 645402001 in words is "six hundred forty-five million, four hundred two thousand, one".