681680234 has 4 divisors (see below), whose sum is σ = 1022520354. Its totient is φ = 340840116.

The previous prime is 681680231. The next prime is 681680257. The reversal of 681680234 is 432086186.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 420373009 + 261307225 = 20503^2 + 16165^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (681680231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 170420057 + ... + 170420060.

Almost surely, 2^681680234 is an apocalyptic number.

681680234 is a deficient number, since it is larger than the sum of its proper divisors (340840120).

681680234 is a wasteful number, since it uses less digits than its factorization.

681680234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340840119.

The product of its (nonzero) digits is 55296, while the sum is 38.

The square root of 681680234 is about 26109.0067601202. The cubic root of 681680234 is about 880.0896232756.

The spelling of 681680234 in words is "six hundred eighty-one million, six hundred eighty thousand, two hundred thirty-four".