681235139 has 8 divisors (see below), whose sum is σ = 772250640. Its totient is φ = 595735776.

The previous prime is 681235133. The next prime is 681235147. The reversal of 681235139 is 931532186.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-681235139 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (681235133) 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, 1378772 + ... + 1379265.

It is an arithmetic number, because the mean of its divisors is an integer number (96531330).

Almost surely, 2^681235139 is an apocalyptic number.

681235139 is a deficient number, since it is larger than the sum of its proper divisors (91015501).

681235139 is a wasteful number, since it uses less digits than its factorization.

681235139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2758069.

The product of its digits is 38880, while the sum is 38.

The square root of 681235139 is about 26100.4815855953. The cubic root of 681235139 is about 879.8980335540.

The spelling of 681235139 in words is "six hundred eighty-one million, two hundred thirty-five thousand, one hundred thirty-nine".