687909401 has 2 divisors, whose sum is σ = 687909402. Its totient is φ = 687909400.

The previous prime is 687909361. The next prime is 687909407. The reversal of 687909401 is 104909786.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 676000000 + 11909401 = 26000^2 + 3451^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-687909401 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (687909407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343954700 + 343954701.

It is an arithmetic number, because the mean of its divisors is an integer number (343954701).

Almost surely, 2^687909401 is an apocalyptic number.

It is an amenable number.

687909401 is a deficient number, since it is larger than the sum of its proper divisors (1).

687909401 is an equidigital number, since it uses as much as digits as its factorization.

687909401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108864, while the sum is 44.

The square root of 687909401 is about 26228.0270131018. The cubic root of 687909401 is about 882.7622403575.

The spelling of 687909401 in words is "six hundred eighty-seven million, nine hundred nine thousand, four hundred one".