645822849 has 16 divisors (see below), whose sum is σ = 998801408. Its totient is φ = 363532752.

The previous prime is 645822847. The next prime is 645822851. The reversal of 645822849 is 948228546.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (645822847) and next prime (645822851).

It is not a de Polignac number, because 645822849 - 2¹ = 645822847 is a prime.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 645822798 and 645822807.

It is not an unprimeable number, because it can be changed into a prime (645822847) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 228097 + ... + 230910.

It is an arithmetic number, because the mean of its divisors is an integer number (62425088).

Almost surely, 2^645822849 is an apocalyptic number.

It is an amenable number.

645822849 is a deficient number, since it is larger than the sum of its proper divisors (352978559).

645822849 is a wasteful number, since it uses less digits than its factorization.

645822849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 459084.

The product of its digits is 1105920, while the sum is 48.

The square root of 645822849 is about 25413.0448588909. The cubic root of 645822849 is about 864.3795204996.

The spelling of 645822849 in words is "six hundred forty-five million, eight hundred twenty-two thousand, eight hundred forty-nine".