644760492611 has 16 divisors (see below), whose sum is σ = 681815650560. Its totient is φ = 608018412960.

The previous prime is 644760492599. The next prime is 644760492641. The reversal of 644760492611 is 116294067446.

It is a cyclic number.

It is not a de Polignac number, because 644760492611 - 2¹⁸ = 644760230467 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 644760492611.

It is not an unprimeable number, because it can be changed into a prime (644760492641) 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 15 ways as a sum of consecutive naturals, for example, 29623745 + ... + 29645501.

It is an arithmetic number, because the mean of its divisors is an integer number (42613478160).

Almost surely, 2^644760492611 is an apocalyptic number.

644760492611 is a deficient number, since it is larger than the sum of its proper divisors (37055157949).

644760492611 is a wasteful number, since it uses less digits than its factorization.

644760492611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28874.

The product of its (nonzero) digits is 1741824, while the sum is 50.

The spelling of 644760492611 in words is "six hundred forty-four billion, seven hundred sixty million, four hundred ninety-two thousand, six hundred eleven".