856641394 has 16 divisors (see below), whose sum is σ = 1532377728. Its totient is φ = 351169632.

The previous prime is 856641389. The next prime is 856641403. The reversal of 856641394 is 493146658.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 1329867 + ... + 1330510.

It is an arithmetic number, because the mean of its divisors is an integer number (95773608).

Almost surely, 2^856641394 is an apocalyptic number.

856641394 is a deficient number, since it is larger than the sum of its proper divisors (675736334).

856641394 is a wasteful number, since it uses less digits than its factorization.

856641394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2660409.

The product of its digits is 622080, while the sum is 46.

The square root of 856641394 is about 29268.4368219418. The cubic root of 856641394 is about 949.7289694057.

The spelling of 856641394 in words is "eight hundred fifty-six million, six hundred forty-one thousand, three hundred ninety-four".