856640343 has 16 divisors (see below), whose sum is σ = 1236431840. Its totient is φ = 524427264.

The previous prime is 856640339. The next prime is 856640357. The reversal of 856640343 is 343046658.

It is not a de Polignac number, because 856640343 - 2² = 856640339 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (856640303) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49378 + ... + 64431.

It is an arithmetic number, because the mean of its divisors is an integer number (77276990).

Almost surely, 2^856640343 is an apocalyptic number.

856640343 is a deficient number, since it is larger than the sum of its proper divisors (379791497).

856640343 is a wasteful number, since it uses less digits than its factorization.

856640343 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114018.

The product of its (nonzero) digits is 207360, while the sum is 39.

The square root of 856640343 is about 29268.4188674414. The cubic root of 856640343 is about 949.7285810029.

The spelling of 856640343 in words is "eight hundred fifty-six million, six hundred forty thousand, three hundred forty-three".