19814971 has 4 divisors (see below), whose sum is σ = 21616344. Its totient is φ = 18013600.

The previous prime is 19814969. The next prime is 19814981. The reversal of 19814971 is 17941891.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 19814971 - 2¹ = 19814969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19814981) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 900670 + ... + 900691.

It is an arithmetic number, because the mean of its divisors is an integer number (5404086).

Almost surely, 2^19814971 is an apocalyptic number.

19814971 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

19814971 is a deficient number, since it is larger than the sum of its proper divisors (1801373).

19814971 is a wasteful number, since it uses less digits than its factorization.

19814971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1801372.

The product of its digits is 18144, while the sum is 40.

The square root of 19814971 is about 4451.4010154108. The cubic root of 19814971 is about 270.6020902900.

Subtracting from 19814971 its reverse (17941891), we obtain a triangular number (1873080 = T₁₉₃₅).

The spelling of 19814971 in words is "nineteen million, eight hundred fourteen thousand, nine hundred seventy-one".