644421474250305 has 32 divisors (see below), whose sum is σ = 1053040852850688. Its totient is φ = 336369687441600.

The previous prime is 644421474250303. The next prime is 644421474250321. The reversal of 644421474250305 is 503052474124446.

It is not a de Polignac number, because 644421474250305 - 2¹ = 644421474250303 is a prime.

It is a super-3 number, since 3×644421474250305³ (a number of 45 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (644421474250303) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13410790 + ... + 38323520.

It is an arithmetic number, because the mean of its divisors is an integer number (32907526651584).

Almost surely, 2^{644421474250305} is an apocalyptic number.

It is an amenable number.

644421474250305 is a deficient number, since it is larger than the sum of its proper divisors (408619378600383).

644421474250305 is a wasteful number, since it uses less digits than its factorization.

644421474250305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24949477.

The product of its (nonzero) digits is 12902400, while the sum is 51.

The spelling of 644421474250305 in words is "six hundred forty-four trillion, four hundred twenty-one billion, four hundred seventy-four million, two hundred fifty thousand, three hundred five".