1981745306515 has 8 divisors (see below), whose sum is σ = 2561024703888. Its totient is φ = 1463442687840.

The previous prime is 1981745306503. The next prime is 1981745306521. The reversal of 1981745306515 is 5156035471891.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-1981745306515 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15244194601 + ... + 15244194730.

It is an arithmetic number, because the mean of its divisors is an integer number (320128087986).

Almost surely, 2^{1981745306515} is an apocalyptic number.

1981745306515 is a deficient number, since it is larger than the sum of its proper divisors (579279397373).

1981745306515 is a wasteful number, since it uses less digits than its factorization.

1981745306515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30488389349.

The product of its (nonzero) digits is 4536000, while the sum is 55.

The spelling of 1981745306515 in words is "one trillion, nine hundred eighty-one billion, seven hundred forty-five million, three hundred six thousand, five hundred fifteen".