681743858 has 4 divisors (see below), whose sum is σ = 1022615790. Its totient is φ = 340871928.

The previous prime is 681743849. The next prime is 681743873. The reversal of 681743858 is 858347186.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 858347186 = 2 ⋅429173593.

It can be written as a sum of positive squares in only one way, i.e., 672520489 + 9223369 = 25933^2 + 3037^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 170435963 + ... + 170435966.

Almost surely, 2^681743858 is an apocalyptic number.

681743858 is a deficient number, since it is larger than the sum of its proper divisors (340871932).

681743858 is a wasteful number, since it uses less digits than its factorization.

681743858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340871931.

The product of its digits is 1290240, while the sum is 50.

The square root of 681743858 is about 26110.2251618020. The cubic root of 681743858 is about 880.1170032100.

The spelling of 681743858 in words is "six hundred eighty-one million, seven hundred forty-three thousand, eight hundred fifty-eight".