612916781 has 2 divisors, whose sum is σ = 612916782. Its totient is φ = 612916780.

The previous prime is 612916771. The next prime is 612916807. The reversal of 612916781 is 187619216.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 551545225 + 61371556 = 23485^2 + 7834^2 .

It is a cyclic number.

It is not a de Polignac number, because 612916781 - 2¹⁰ = 612915757 is a prime.

It is a super-2 number, since 2×612916781² = 751333960862803922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (612916741) 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, 306458390 + 306458391.

It is an arithmetic number, because the mean of its divisors is an integer number (306458391).

Almost surely, 2^612916781 is an apocalyptic number.

It is an amenable number.

612916781 is a deficient number, since it is larger than the sum of its proper divisors (1).

612916781 is an equidigital number, since it uses as much as digits as its factorization.

612916781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36288, while the sum is 41.

The square root of 612916781 is about 24757.1561573619. The cubic root of 612916781 is about 849.4422088995.

The spelling of 612916781 in words is "six hundred twelve million, nine hundred sixteen thousand, seven hundred eighty-one".