681771042 has 24 divisors (see below), whose sum is σ = 1513200780. Its totient is φ = 221713920.

The previous prime is 681771031. The next prime is 681771067. The reversal of 681771042 is 240177186.

It can be written as a sum of positive squares in 2 ways, for example, as 679175721 + 2595321 = 26061^2 + 1611^2 .

It is a junction number, because it is equal to n+sod(n) for n = 681770988 and 681771006.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 461167 + ... + 462642.

Almost surely, 2^681771042 is an apocalyptic number.

681771042 is an abundant number, since it is smaller than the sum of its proper divisors (831429738).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

681771042 is a wasteful number, since it uses less digits than its factorization.

681771042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 923858 (or 923855 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The square root of 681771042 is about 26110.7457189564. The cubic root of 681771042 is about 880.1287010455.

The spelling of 681771042 in words is "six hundred eighty-one million, seven hundred seventy-one thousand, forty-two".