613881 has 6 divisors (see below), whose sum is σ = 886730. Its totient is φ = 409248.

The previous prime is 613861. The next prime is 613883. The reversal of 613881 is 188316.

It can be written as a sum of positive squares in only one way, i.e., 518400 + 95481 = 720^2 + 309^2 .

It is not a de Polignac number, because 613881 - 2⁵ = 613849 is a prime.

It is a super-2 number, since 2×613881² = 753699764322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (613883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 34096 + ... + 34113.

2⁶¹³⁸⁸¹ is an apocalyptic number.

It is an amenable number.

613881 is a deficient number, since it is larger than the sum of its proper divisors (272849).

613881 is a wasteful number, since it uses less digits than its factorization.

613881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68215 (or 68212 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 613881 is about 783.5055838984. The cubic root of 613881 is about 84.9887413000.

The spelling of 613881 in words is "six hundred thirteen thousand, eight hundred eighty-one".