1644081967513 has 4 divisors (see below), whose sum is σ = 1648819956240. Its totient is φ = 1639343978788.

The previous prime is 1644081967499. The next prime is 1644081967529. The reversal of 1644081967513 is 3157691804461.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1644081967513 is a prime.

It is a super-3 number, since 3×1644081967513³ (a number of 38 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1644081967573) 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, 2368993843 + ... + 2368994536.

It is an arithmetic number, because the mean of its divisors is an integer number (412204989060).

Almost surely, 2^{1644081967513} is an apocalyptic number.

It is an amenable number.

1644081967513 is a deficient number, since it is larger than the sum of its proper divisors (4737988727).

1644081967513 is an equidigital number, since it uses as much as digits as its factorization.

1644081967513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4737988726.

The product of its (nonzero) digits is 4354560, while the sum is 55.

The spelling of 1644081967513 in words is "one trillion, six hundred forty-four billion, eighty-one million, nine hundred sixty-seven thousand, five hundred thirteen".