857240645 has 4 divisors (see below), whose sum is σ = 1028688780. Its totient is φ = 685792512.

The previous prime is 857240641. The next prime is 857240653. The reversal of 857240645 is 546042758.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 609398596 + 247842049 = 24686^2 + 15743^2 .

It is a cyclic number.

It is not a de Polignac number, because 857240645 - 2² = 857240641 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (857240641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 85724060 + ... + 85724069.

It is an arithmetic number, because the mean of its divisors is an integer number (257172195).

Almost surely, 2^857240645 is an apocalyptic number.

It is an amenable number.

857240645 is a deficient number, since it is larger than the sum of its proper divisors (171448135).

857240645 is a wasteful number, since it uses less digits than its factorization.

857240645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171448134.

The product of its (nonzero) digits is 268800, while the sum is 41.

The square root of 857240645 is about 29278.6721864227. The cubic root of 857240645 is about 949.9503741390.

The spelling of 857240645 in words is "eight hundred fifty-seven million, two hundred forty thousand, six hundred forty-five".