687055381 has 2 divisors, whose sum is σ = 687055382. Its totient is φ = 687055380.

The previous prime is 687055363. The next prime is 687055399. The reversal of 687055381 is 183550786.

687055381 = 18534² + 18535².

It is a balanced prime because it is at equal distance from previous prime (687055363) and next prime (687055399).

It can be written as a sum of positive squares in only one way, i.e., 343546225 + 343509156 = 18535^2 + 18534^2 .

It is a cyclic number.

It is not a de Polignac number, because 687055381 - 2⁵ = 687055349 is a prime.

It is a super-2 number, since 2×687055381² = 944090193122110322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (687055351) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343527690 + 343527691.

It is an arithmetic number, because the mean of its divisors is an integer number (343527691).

Almost surely, 2^687055381 is an apocalyptic number.

687055381 is the 18535-th centered square number.

It is an amenable number.

687055381 is a deficient number, since it is larger than the sum of its proper divisors (1).

687055381 is an equidigital number, since it uses as much as digits as its factorization.

687055381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 201600, while the sum is 43.

The square root of 687055381 is about 26211.7412813418. The cubic root of 687055381 is about 882.3967809898.

The spelling of 687055381 in words is "six hundred eighty-seven million, fifty-five thousand, three hundred eighty-one".