681265350544 has 15 divisors (see below), whose sum is σ = 1319958013467. Its totient is φ = 340631024496.

The previous prime is 681265350533. The next prime is 681265350547. The reversal of 681265350544 is 445053562186.

The square root of 681265350544 is 825388.

It is a perfect power (a square), and thus also a powerful number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (681265350547) 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 2 ways as a sum of consecutive naturals, for example, 3198379 + ... + 3404725.

Almost surely, 2^681265350544 is an apocalyptic number.

681265350544 is the 825388-th square number.

It is an amenable number.

681265350544 is a deficient number, since it is larger than the sum of its proper divisors (638692662923).

681265350544 is an frugal number, since it uses more digits than its factorization.

681265350544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 412702 (or 206349 counting only the distinct ones).

The product of its (nonzero) digits is 3456000, while the sum is 49.

Multiplying 681265350544 by its sum of digits (49), we get a square (33382002176656 = 5777716²).

The spelling of 681265350544 in words is "six hundred eighty-one billion, two hundred sixty-five million, three hundred fifty thousand, five hundred forty-four".