681920234 has 4 divisors (see below), whose sum is σ = 1022880354. Its totient is φ = 340960116.

The previous prime is 681920209. The next prime is 681920257. The reversal of 681920234 is 432029186.

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., 675844009 + 6076225 = 25997^2 + 2465^2 .

It is a super-3 number, since 3×681920234³ (a number of 27 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 681920194 and 681920203.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 170480057 + ... + 170480060.

Almost surely, 2^681920234 is an apocalyptic number.

681920234 is a deficient number, since it is larger than the sum of its proper divisors (340960120).

681920234 is a wasteful number, since it uses less digits than its factorization.

681920234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340960119.

The product of its (nonzero) digits is 20736, while the sum is 35.

The square root of 681920234 is about 26113.6024707431. The cubic root of 681920234 is about 880.1928959029.

The spelling of 681920234 in words is "six hundred eighty-one million, nine hundred twenty thousand, two hundred thirty-four".