7681213 has 2 divisors, whose sum is σ = 7681214. Its totient is φ = 7681212.

The previous prime is 7681199. The next prime is 7681231. The reversal of 7681213 is 3121867.

Together with next prime (7681231) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5555449 + 2125764 = 2357^2 + 1458^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7681213 is a prime.

It is the 2772-nd Hogben number.

7681213 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7681243) by changing a digit.

It is a nontrivial repunit in base 2771.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3840606 + 3840607.

It is an arithmetic number, because the mean of its divisors is an integer number (3840607).

Almost surely, 2^7681213 is an apocalyptic number.

It is an amenable number.

7681213 is a deficient number, since it is larger than the sum of its proper divisors (1).

7681213 is an equidigital number, since it uses as much as digits as its factorization.

7681213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2016, while the sum is 28.

The square root of 7681213 is about 2771.5001353058. The cubic root of 7681213 is about 197.3073526053.

The spelling of 7681213 in words is "seven million, six hundred eighty-one thousand, two hundred thirteen".