19638971 has 16 divisors (see below), whose sum is σ = 22338528. Its totient is φ = 17107200.

The previous prime is 19638967. The next prime is 19638977. The reversal of 19638971 is 17983691.

It is not a de Polignac number, because 19638971 - 2² = 19638967 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19638977) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29381 + ... + 30041.

It is an arithmetic number, because the mean of its divisors is an integer number (1396158).

Almost surely, 2^19638971 is an apocalyptic number.

19638971 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

19638971 is a deficient number, since it is larger than the sum of its proper divisors (2699557).

19638971 is a wasteful number, since it uses less digits than its factorization.

19638971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 782.

The product of its digits is 81648, while the sum is 44.

The square root of 19638971 is about 4431.5878644116. The cubic root of 19638971 is about 269.7985282560.

The spelling of 19638971 in words is "nineteen million, six hundred thirty-eight thousand, nine hundred seventy-one".