687222397 has 2 divisors, whose sum is σ = 687222398. Its totient is φ = 687222396.

The previous prime is 687222379. The next prime is 687222407. The reversal of 687222397 is 793222786.

Together with previous prime (687222379) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 680740281 + 6482116 = 26091^2 + 2546^2 .

It is a cyclic number.

It is not a de Polignac number, because 687222397 - 2¹¹ = 687220349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (687222307) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343611198 + 343611199.

It is an arithmetic number, because the mean of its divisors is an integer number (343611199).

Almost surely, 2^687222397 is an apocalyptic number.

It is an amenable number.

687222397 is a deficient number, since it is larger than the sum of its proper divisors (1).

687222397 is an equidigital number, since it uses as much as digits as its factorization.

687222397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 508032, while the sum is 46.

The square root of 687222397 is about 26214.9269882638. The cubic root of 687222397 is about 882.4682756828.

The spelling of 687222397 in words is "six hundred eighty-seven million, two hundred twenty-two thousand, three hundred ninety-seven".