20840356 has 12 divisors (see below), whose sum is σ = 36505840. Its totient is φ = 10410120.

The previous prime is 20840311. The next prime is 20840363. The reversal of 20840356 is 65304802.

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 3 ways as a sum of consecutive naturals, for example, 4051 + ... + 7621.

Almost surely, 2^20840356 is an apocalyptic number.

It is an amenable number.

20840356 is a deficient number, since it is larger than the sum of its proper divisors (15665484).

20840356 is a wasteful number, since it uses less digits than its factorization.

20840356 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5034 (or 5032 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 20840356 is about 4565.1238756467. The cubic root of 20840356 is about 275.1915183804.

The spelling of 20840356 in words is "twenty million, eight hundred forty thousand, three hundred fifty-six".