1685139337781 has 4 divisors (see below), whose sum is σ = 1685142217152. Its totient is φ = 1685136458412.

The previous prime is 1685139337643. The next prime is 1685139337789. The reversal of 1685139337781 is 1877339315861.

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-1685139337781 is a prime.

It is a super-2 number, since 2×1685139337781² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1685139337789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 213965 + ... + 1848258.

It is an arithmetic number, because the mean of its divisors is an integer number (421285554288).

Almost surely, 2^{1685139337781} is an apocalyptic number.

It is an amenable number.

1685139337781 is a deficient number, since it is larger than the sum of its proper divisors (2879371).

1685139337781 is an equidigital number, since it uses as much as digits as its factorization.

1685139337781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2879370.

The product of its digits is 22861440, while the sum is 62.

The spelling of 1685139337781 in words is "one trillion, six hundred eighty-five billion, one hundred thirty-nine million, three hundred thirty-seven thousand, seven hundred eighty-one".