645321651046433 has 4 divisors (see below), whose sum is σ = 645322704281748. Its totient is φ = 645320597811120.

The previous prime is 645321651046411. The next prime is 645321651046439. The reversal of 645321651046433 is 334640156123546.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 401977157199424 + 243344493847009 = 20049368^2 + 15599503^2 .

It is a cyclic number.

It is not a de Polignac number, because 645321651046433 - 2¹² = 645321651042337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (645321651046439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 525698066 + ... + 526924187.

It is an arithmetic number, because the mean of its divisors is an integer number (161330676070437).

Almost surely, 2^{645321651046433} is an apocalyptic number.

It is an amenable number.

645321651046433 is a deficient number, since it is larger than the sum of its proper divisors (1053235315).

645321651046433 is a wasteful number, since it uses less digits than its factorization.

645321651046433 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1053235314.

The product of its (nonzero) digits is 18662400, while the sum is 53.

The spelling of 645321651046433 in words is "six hundred forty-five trillion, three hundred twenty-one billion, six hundred fifty-one million, forty-six thousand, four hundred thirty-three".