857284621 has 4 divisors (see below), whose sum is σ = 878194044. Its totient is φ = 836375200.

The previous prime is 857284583. The next prime is 857284627. The reversal of 857284621 is 126482758.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 126482758 = 2 ⋅63241379.

It can be written as a sum of positive squares in 2 ways, for example, as 79655625 + 777628996 = 8925^2 + 27886^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-857284621 is a prime.

It is a super-2 number, since 2×857284621² = 1469873842806227282, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (857284627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10454650 + ... + 10454731.

It is an arithmetic number, because the mean of its divisors is an integer number (219548511).

Almost surely, 2^857284621 is an apocalyptic number.

It is an amenable number.

857284621 is a deficient number, since it is larger than the sum of its proper divisors (20909423).

857284621 is a wasteful number, since it uses less digits than its factorization.

857284621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20909422.

The product of its digits is 215040, while the sum is 43.

The square root of 857284621 is about 29279.4231671322. The cubic root of 857284621 is about 949.9666178482.

The spelling of 857284621 in words is "eight hundred fifty-seven million, two hundred eighty-four thousand, six hundred twenty-one".