681378242 has 8 divisors (see below), whose sum is σ = 1023079356. Its totient is φ = 340351792.

The previous prime is 681378227. The next prime is 681378307. The reversal of 681378242 is 242873186.

It can be written as a sum of positive squares in 2 ways, for example, as 598731961 + 82646281 = 24469^2 + 9091^2 .

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

It is a self number, because there is not a number n which added to its sum of digits gives 681378242.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 166133 + ... + 170184.

Almost surely, 2^681378242 is an apocalyptic number.

681378242 is a deficient number, since it is larger than the sum of its proper divisors (341701114).

681378242 is a wasteful number, since it uses less digits than its factorization.

681378242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 337332.

The product of its digits is 129024, while the sum is 41.

The square root of 681378242 is about 26103.2228278425. Note that the first 3 decimals coincide. The cubic root of 681378242 is about 879.9596408832.

The spelling of 681378242 in words is "six hundred eighty-one million, three hundred seventy-eight thousand, two hundred forty-two".