644292849307 has 4 divisors (see below), whose sum is σ = 682192428696. Its totient is φ = 606393269920.

The previous prime is 644292849251. The next prime is 644292849313. The reversal of 644292849307 is 703948292446.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-644292849307 is a prime.

It is a super-2 number, since 2×644292849307² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (644292849337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18949789669 + ... + 18949789702.

It is an arithmetic number, because the mean of its divisors is an integer number (170548107174).

Almost surely, 2^644292849307 is an apocalyptic number.

644292849307 is a deficient number, since it is larger than the sum of its proper divisors (37899579389).

644292849307 is a wasteful number, since it uses less digits than its factorization.

644292849307 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37899579388.

The product of its (nonzero) digits is 20901888, while the sum is 58.

The spelling of 644292849307 in words is "six hundred forty-four billion, two hundred ninety-two million, eight hundred forty-nine thousand, three hundred seven".