21971467 has 24 divisors (see below), whose sum is σ = 27663360. Its totient is φ = 17029440.

The previous prime is 21971459. The next prime is 21971479. The reversal of 21971467 is 76417912.

It is not a de Polignac number, because 21971467 - 2³ = 21971459 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21971437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 300943 + ... + 301015.

It is an arithmetic number, because the mean of its divisors is an integer number (1152640).

Almost surely, 2^21971467 is an apocalyptic number.

21971467 is a deficient number, since it is larger than the sum of its proper divisors (5691893).

21971467 is an equidigital number, since it uses as much as digits as its factorization.

21971467 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 203 (or 130 counting only the distinct ones).

The product of its digits is 21168, while the sum is 37.

The square root of 21971467 is about 4687.3731449502. The cubic root of 21971467 is about 280.0827434031.

The spelling of 21971467 in words is "twenty-one million, nine hundred seventy-one thousand, four hundred sixty-seven".