21194971 has 12 divisors (see below), whose sum is σ = 25733968. Its totient is φ = 17096832.

The previous prime is 21194959. The next prime is 21194977. The reversal of 21194971 is 17949112.

It is not a de Polignac number, because 21194971 - 2¹⁵ = 21162203 is a prime.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21194977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3216 + ... + 7261.

Almost surely, 2^21194971 is an apocalyptic number.

21194971 is a deficient number, since it is larger than the sum of its proper divisors (4538997).

21194971 is a wasteful number, since it uses less digits than its factorization.

21194971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10518 (or 10501 counting only the distinct ones).

The product of its digits is 4536, while the sum is 34.

The square root of 21194971 is about 4603.7996263956. The cubic root of 21194971 is about 276.7436145060.

The spelling of 21194971 in words is "twenty-one million, one hundred ninety-four thousand, nine hundred seventy-one".