681038781 has 8 divisors (see below), whose sum is σ = 916868160. Its totient is φ = 449617632.

The previous prime is 681038777. The next prime is 681038791. The reversal of 681038781 is 187830186.

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

It is not a de Polignac number, because 681038781 - 2² = 681038777 is a prime.

It is a super-2 number, since 2×681038781² = 927627642451931922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681038731) 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, 1101696 + ... + 1102313.

It is an arithmetic number, because the mean of its divisors is an integer number (114608520).

Almost surely, 2^681038781 is an apocalyptic number.

It is an amenable number.

681038781 is a deficient number, since it is larger than the sum of its proper divisors (235829379).

681038781 is a wasteful number, since it uses less digits than its factorization.

681038781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2204115.

The product of its (nonzero) digits is 64512, while the sum is 42.

The square root of 681038781 is about 26096.7197363960. The cubic root of 681038781 is about 879.8134853508.

The spelling of 681038781 in words is "six hundred eighty-one million, thirty-eight thousand, seven hundred eighty-one".