613663891 has 2 divisors, whose sum is σ = 613663892. Its totient is φ = 613663890.

The previous prime is 613663847. The next prime is 613663901. The reversal of 613663891 is 198366316.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 613663891 - 2⁷ = 613663763 is a prime.

It is a super-2 number, since 2×613663891² = 753166742234519762, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (613663091) 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 as a sum of consecutive naturals, namely, 306831945 + 306831946.

It is an arithmetic number, because the mean of its divisors is an integer number (306831946).

Almost surely, 2^613663891 is an apocalyptic number.

613663891 is a deficient number, since it is larger than the sum of its proper divisors (1).

613663891 is an equidigital number, since it uses as much as digits as its factorization.

613663891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 139968, while the sum is 43.

The square root of 613663891 is about 24772.2403306604. The cubic root of 613663891 is about 849.7872090176.

The spelling of 613663891 in words is "six hundred thirteen million, six hundred sixty-three thousand, eight hundred ninety-one".