645202783 has 4 divisors (see below), whose sum is σ = 666015808. Its totient is φ = 624389760.

The previous prime is 645202771. The next prime is 645202787. The reversal of 645202783 is 387202546.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 387202546 = 2 ⋅193601273.

It is a cyclic number.

It is not a de Polignac number, because 645202783 - 2¹⁷ = 645071711 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 (645202787) 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, 10406466 + ... + 10406527.

It is an arithmetic number, because the mean of its divisors is an integer number (166503952).

Almost surely, 2^645202783 is an apocalyptic number.

645202783 is a deficient number, since it is larger than the sum of its proper divisors (20813025).

645202783 is a wasteful number, since it uses less digits than its factorization.

645202783 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20813024.

The product of its (nonzero) digits is 80640, while the sum is 37.

The square root of 645202783 is about 25400.8421710777. The cubic root of 645202783 is about 864.1027965360.

The spelling of 645202783 in words is "six hundred forty-five million, two hundred two thousand, seven hundred eighty-three".