645249860999 has 4 divisors (see below), whose sum is σ = 645272703336. Its totient is φ = 645227018664.

The previous prime is 645249860951. The next prime is 645249861001. The reversal of 645249860999 is 999068942546.

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 645249860999 - 2²⁴ = 645233083783 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 (645249860399) 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, 11378744 + ... + 11435309.

It is an arithmetic number, because the mean of its divisors is an integer number (161318175834).

Almost surely, 2^645249860999 is an apocalyptic number.

645249860999 is a deficient number, since it is larger than the sum of its proper divisors (22842337).

645249860999 is a wasteful number, since it uses less digits than its factorization.

645249860999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22842336.

The product of its (nonzero) digits is 302330880, while the sum is 71.

The spelling of 645249860999 in words is "six hundred forty-five billion, two hundred forty-nine million, eight hundred sixty thousand, nine hundred ninety-nine".