616681 has 12 divisors (see below), whose sum is σ = 691740. Its totient is φ = 549120.

The previous prime is 616673. The next prime is 616703. The reversal of 616681 is 186616.

616681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 6 ways, for example, as 341056 + 275625 = 584^2 + 525^2 .

It is not a de Polignac number, because 616681 - 2³ = 616673 is a prime.

It is a super-2 number, since 2×616681² = 760590911522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (616181) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6885 + ... + 6973.

It is an arithmetic number, because the mean of its divisors is an integer number (57645).

2⁶¹⁶⁶⁸¹ is an apocalyptic number.

It is an amenable number.

616681 is a deficient number, since it is larger than the sum of its proper divisors (75059).

616681 is a wasteful number, since it uses less digits than its factorization.

616681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156 (or 143 counting only the distinct ones).

The product of its digits is 1728, while the sum is 28.

The square root of 616681 is about 785.2903921480. The cubic root of 616681 is about 85.1177606522.

The spelling of 616681 in words is "six hundred sixteen thousand, six hundred eighty-one".