68490387813 has 4 divisors (see below), whose sum is σ = 91320517088. Its totient is φ = 45660258540.

The previous prime is 68490387811. The next prime is 68490387841. The reversal of 68490387813 is 31878309486.

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 not a de Polignac number, because 68490387813 - 2¹ = 68490387811 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68490387811) 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 3 ways as a sum of consecutive naturals, for example, 11415064633 + ... + 11415064638.

It is an arithmetic number, because the mean of its divisors is an integer number (22830129272).

Almost surely, 2^68490387813 is an apocalyptic number.

It is an amenable number.

68490387813 is a deficient number, since it is larger than the sum of its proper divisors (22830129275).

68490387813 is a wasteful number, since it uses less digits than its factorization.

68490387813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22830129274.

The product of its (nonzero) digits is 6967296, while the sum is 57.

The spelling of 68490387813 in words is "sixty-eight billion, four hundred ninety million, three hundred eighty-seven thousand, eight hundred thirteen".