21971214 has 12 divisors (see below), whose sum is σ = 47604336. Its totient is φ = 7323732.

The previous prime is 21971197. The next prime is 21971221. The reversal of 21971214 is 41217912.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 610294 + ... + 610329.

It is an arithmetic number, because the mean of its divisors is an integer number (3967028).

Almost surely, 2^21971214 is an apocalyptic number.

21971214 is an abundant number, since it is smaller than the sum of its proper divisors (25633122).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21971214 is a wasteful number, since it uses less digits than its factorization.

21971214 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1220631 (or 1220628 counting only the distinct ones).

The product of its digits is 1008, while the sum is 27.

The square root of 21971214 is about 4687.3461574755. The cubic root of 21971214 is about 280.0816683541.

It can be divided in two parts, 2 and 1971214, that added together give a square (1971216 = 1404²).

The spelling of 21971214 in words is "twenty-one million, nine hundred seventy-one thousand, two hundred fourteen".