685408151 has 2 divisors, whose sum is σ = 685408152. Its totient is φ = 685408150.

The previous prime is 685408121. The next prime is 685408153. The reversal of 685408151 is 151804586.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 685408151 - 2²² = 681213847 is a prime.

It is a Sophie Germain prime.

Together with 685408153, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_35535791 and since 685408151 and 35535791 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (685408153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342704075 + 342704076.

It is an arithmetic number, because the mean of its divisors is an integer number (342704076).

Almost surely, 2^685408151 is an apocalyptic number.

685408151 is a deficient number, since it is larger than the sum of its proper divisors (1).

685408151 is an equidigital number, since it uses as much as digits as its factorization.

685408151 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 38400, while the sum is 38.

The square root of 685408151 is about 26180.3008195093. The cubic root of 685408151 is about 881.6910282723.

The spelling of 685408151 in words is "six hundred eighty-five million, four hundred eight thousand, one hundred fifty-one".