681109031 has 4 divisors (see below), whose sum is σ = 682416864. Its totient is φ = 679801200.

The previous prime is 681109021. The next prime is 681109043. The reversal of 681109031 is 130901186.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-681109031 is a prime.

It is a super-2 number, since 2×681109031² = 927819024219517922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 681108985 and 681109003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681109021) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 653135 + ... + 654176.

It is an arithmetic number, because the mean of its divisors is an integer number (170604216).

Almost surely, 2^681109031 is an apocalyptic number.

681109031 is a deficient number, since it is larger than the sum of its proper divisors (1307833).

681109031 is a wasteful number, since it uses less digits than its factorization.

681109031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1307832.

The product of its (nonzero) digits is 1296, while the sum is 29.

The square root of 681109031 is about 26098.0656562895. The cubic root of 681109031 is about 879.8437355969.

The spelling of 681109031 in words is "six hundred eighty-one million, one hundred nine thousand, thirty-one".