645421573423 has 8 divisors (see below), whose sum is σ = 704591076096. Its totient is φ = 586334539800.

The previous prime is 645421573409. The next prime is 645421573429. The reversal of 645421573423 is 324375124546.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 645421573423 - 2³⁷ = 507982619951 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645421573429) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20600893 + ... + 20632198.

It is an arithmetic number, because the mean of its divisors is an integer number (88073884512).

Almost surely, 2^645421573423 is an apocalyptic number.

645421573423 is a deficient number, since it is larger than the sum of its proper divisors (59169502673).

645421573423 is a wasteful number, since it uses less digits than its factorization.

645421573423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41234525.

The product of its digits is 2419200, while the sum is 46.

Adding to 645421573423 its reverse (324375124546), we get a palindrome (969796697969).

The spelling of 645421573423 in words is "six hundred forty-five billion, four hundred twenty-one million, five hundred seventy-three thousand, four hundred twenty-three".