613281991 has 12 divisors (see below), whose sum is σ = 728591328. Its totient is φ = 514483872.

The previous prime is 613281989. The next prime is 613282013. The reversal of 613281991 is 199182316.

613281991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 613281991 - 2¹ = 613281989 is a prime.

It is a super-2 number, since 2×613281991² = 752229600969848162, 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 (613281941) 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, 130846 + ... + 135451.

It is an arithmetic number, because the mean of its divisors is an integer number (60715944).

Almost surely, 2^613281991 is an apocalyptic number.

613281991 is a deficient number, since it is larger than the sum of its proper divisors (115309337).

613281991 is a wasteful number, since it uses less digits than its factorization.

613281991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266358 (or 266351 counting only the distinct ones).

The product of its digits is 23328, while the sum is 40.

The square root of 613281991 is about 24764.5309061165. The cubic root of 613281991 is about 849.6108904143.

The spelling of 613281991 in words is "six hundred thirteen million, two hundred eighty-one thousand, nine hundred ninety-one".