687071641 has 2 divisors, whose sum is σ = 687071642. Its totient is φ = 687071640.

The previous prime is 687071629. The next prime is 687071647. The reversal of 687071641 is 146170786.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 444366400 + 242705241 = 21080^2 + 15579^2 .

It is a cyclic number.

It is not a de Polignac number, because 687071641 - 2⁷ = 687071513 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 687071594 and 687071603.

It is not a weakly prime, because it can be changed into another prime (687071647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343535820 + 343535821.

It is an arithmetic number, because the mean of its divisors is an integer number (343535821).

Almost surely, 2^687071641 is an apocalyptic number.

It is an amenable number.

687071641 is a deficient number, since it is larger than the sum of its proper divisors (1).

687071641 is an equidigital number, since it uses as much as digits as its factorization.

687071641 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 56448, while the sum is 40.

The square root of 687071641 is about 26212.0514458522. The cubic root of 687071641 is about 882.4037419320.

The spelling of 687071641 in words is "six hundred eighty-seven million, seventy-one thousand, six hundred forty-one".