681542864 has 40 divisors (see below), whose sum is σ = 1352080128. Its totient is φ = 332657280.

The previous prime is 681542839. The next prime is 681542867. The reversal of 681542864 is 468245186.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681542867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 365294 + ... + 367154.

Almost surely, 2^681542864 is an apocalyptic number.

It is an amenable number.

681542864 is a deficient number, since it is larger than the sum of its proper divisors (670537264).

681542864 is a wasteful number, since it uses less digits than its factorization.

681542864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2403 (or 2397 counting only the distinct ones).

The product of its digits is 368640, while the sum is 44.

The square root of 681542864 is about 26106.3759261986. The cubic root of 681542864 is about 880.0305016976.

The spelling of 681542864 in words is "six hundred eighty-one million, five hundred forty-two thousand, eight hundred sixty-four".