19855971 has 6 divisors (see below), whose sum is σ = 28680860. Its totient is φ = 13237308.

The previous prime is 19855961. The next prime is 19855993. The reversal of 19855971 is 17955891.

19855971 is a `hidden beast` number, since 1 + 98 + 559 + 7 + 1 = 666.

It is not a de Polignac number, because 19855971 - 2⁶ = 19855907 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19855921) 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, 1103101 + ... + 1103118.

Almost surely, 2^19855971 is an apocalyptic number.

19855971 is a deficient number, since it is larger than the sum of its proper divisors (8824889).

19855971 is a wasteful number, since it uses less digits than its factorization.

19855971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2206225 (or 2206222 counting only the distinct ones).

The product of its digits is 113400, while the sum is 45.

The square root of 19855971 is about 4456.0039272873. The cubic root of 19855971 is about 270.7885998123.

It can be divided in two parts, 198 and 55971, that added together give a square (56169 = 237²).

The spelling of 19855971 in words is "nineteen million, eight hundred fifty-five thousand, nine hundred seventy-one".