645226409743 has 4 divisors (see below), whose sum is σ = 666040164928. Its totient is φ = 624412654560.

The previous prime is 645226409683. The next prime is 645226409753. The reversal of 645226409743 is 347904622546.

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

It is a cyclic number.

It is not a de Polignac number, because 645226409743 - 2¹³ = 645226401551 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 (645226409753) 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, 10406877546 + ... + 10406877607.

It is an arithmetic number, because the mean of its divisors is an integer number (166510041232).

Almost surely, 2^645226409743 is an apocalyptic number.

645226409743 is a deficient number, since it is larger than the sum of its proper divisors (20813755185).

645226409743 is a wasteful number, since it uses less digits than its factorization.

645226409743 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20813755184.

The product of its (nonzero) digits is 8709120, while the sum is 52.

The spelling of 645226409743 in words is "six hundred forty-five billion, two hundred twenty-six million, four hundred nine thousand, seven hundred forty-three".