2857644 has 18 divisors (see below), whose sum is σ = 7223580. Its totient is φ = 952536.

The previous prime is 2857643. The next prime is 2857661. The reversal of 2857644 is 4467582.

2857644 is a `hidden beast` number, since 2 + 8 + 5 + 7 + 644 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×2857644² = 16332258461472, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 79379 = 2857644 / (2 + 8 + 5 + 7 + 6 + 4 + 4).

It is a d-powerful number, because it can be written as 2¹⁵ + 8³ + 5⁹ + 7⁷ + 6⁶ + 4² + 4⁵ .

It is a junction number, because it is equal to n+sod(n) for n = 2857599 and 2857608.

It is not an unprimeable number, because it can be changed into a prime (2857643) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 39654 + ... + 39725.

It is an arithmetic number, because the mean of its divisors is an integer number (401310).

2^2857644 is an apocalyptic number.

It is an amenable number.

2857644 is an abundant number, since it is smaller than the sum of its proper divisors (4365936).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2857644 is a wasteful number, since it uses less digits than its factorization.

2857644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79389 (or 79384 counting only the distinct ones).

The product of its digits is 53760, while the sum is 36.

The square root of 2857644 is about 1690.4567430136. The cubic root of 2857644 is about 141.9066370350.

The spelling of 2857644 in words is "two million, eight hundred fifty-seven thousand, six hundred forty-four".