644625156064263 has 32 divisors (see below), whose sum is σ = 940927731471360. Its totient is φ = 389312271384960.

The previous prime is 644625156064261. The next prime is 644625156064277. The reversal of 644625156064263 is 362460651526446.

It is not a de Polignac number, because 644625156064263 - 2¹ = 644625156064261 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 644625156064197 and 644625156064206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644625156064261) 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, 5374668 + ... + 36306161.

It is an arithmetic number, because the mean of its divisors is an integer number (29403991608480).

Almost surely, 2^{644625156064263} is an apocalyptic number.

644625156064263 is a deficient number, since it is larger than the sum of its proper divisors (296302575407097).

644625156064263 is a wasteful number, since it uses less digits than its factorization.

644625156064263 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41682487.

The product of its (nonzero) digits is 149299200, while the sum is 60.

The spelling of 644625156064263 in words is "six hundred forty-four trillion, six hundred twenty-five billion, one hundred fifty-six million, sixty-four thousand, two hundred sixty-three".