645819015 has 32 divisors (see below), whose sum is σ = 1054690560. Its totient is φ = 337353984.

The previous prime is 645819011. The next prime is 645819019. The reversal of 645819015 is 510918546.

It is an interprime number because it is at equal distance from previous prime (645819011) and next prime (645819019).

It is not a de Polignac number, because 645819015 - 2² = 645819011 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645819011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 270507 + ... + 272883.

It is an arithmetic number, because the mean of its divisors is an integer number (32959080).

Almost surely, 2^645819015 is an apocalyptic number.

645819015 is a deficient number, since it is larger than the sum of its proper divisors (408871545).

645819015 is a wasteful number, since it uses less digits than its factorization.

645819015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2751.

The product of its (nonzero) digits is 43200, while the sum is 39.

The square root of 645819015 is about 25412.9694250790. The cubic root of 645819015 is about 864.3778100008.

The spelling of 645819015 in words is "six hundred forty-five million, eight hundred nineteen thousand, fifteen".