2120656 has 10 divisors (see below), whose sum is σ = 4108802. Its totient is φ = 1060320.

The previous prime is 2120653. The next prime is 2120693. The reversal of 2120656 is 6560212.

It can be written as a sum of positive squares in only one way, i.e., 2005056 + 115600 = 1416^2 + 340^2 .

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2120653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 66255 + ... + 66286.

2^2120656 is an apocalyptic number.

It is an amenable number.

2120656 is a deficient number, since it is larger than the sum of its proper divisors (1988146).

2120656 is a wasteful number, since it uses less digits than its factorization.

2120656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132549 (or 132543 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 2120656 is about 1456.2472317570. The cubic root of 2120656 is about 128.4764146936.

Subtracting from 2120656 its product of nonzero digits (720), we obtain a square (2119936 = 1456²).

Adding to 2120656 its reverse (6560212), we get a palindrome (8680868).

The spelling of 2120656 in words is "two million, one hundred twenty thousand, six hundred fifty-six".