20855403 has 6 divisors (see below), whose sum is σ = 30124484. Its totient is φ = 13903596.

The previous prime is 20855377. The next prime is 20855423. The reversal of 20855403 is 30455802.

20855403 is a `hidden beast` number, since 208 + 55 + 403 = 666.

It is not a de Polignac number, because 20855403 - 2⁵ = 20855371 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20855423) 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, 1158625 + ... + 1158642.

Almost surely, 2^20855403 is an apocalyptic number.

20855403 is a deficient number, since it is larger than the sum of its proper divisors (9269081).

20855403 is a wasteful number, since it uses less digits than its factorization.

20855403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2317273 (or 2317270 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The square root of 20855403 is about 4566.7716167989. The cubic root of 20855403 is about 275.2577330300.

It can be divided in two parts, 208 and 55403, that added together give a triangular number (55611 = T₃₃₃).

The spelling of 20855403 in words is "twenty million, eight hundred fifty-five thousand, four hundred three".