681890631 has 8 divisors (see below), whose sum is σ = 909323760. Its totient is φ = 454525632.

The previous prime is 681890611. The next prime is 681890653. The reversal of 681890631 is 136098186.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 681890631 - 2⁹ = 681890119 is a prime.

It is a super-2 number, since 2×681890631² = 929949665291156322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681890611) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14851 + ... + 39803.

It is an arithmetic number, because the mean of its divisors is an integer number (113665470).

Almost surely, 2^681890631 is an apocalyptic number.

681890631 is a deficient number, since it is larger than the sum of its proper divisors (227433129).

681890631 is a wasteful number, since it uses less digits than its factorization.

681890631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34065.

The product of its (nonzero) digits is 62208, while the sum is 42.

The square root of 681890631 is about 26113.0356527157. The cubic root of 681890631 is about 880.1801589648.

The spelling of 681890631 in words is "six hundred eighty-one million, eight hundred ninety thousand, six hundred thirty-one".