21971282 has 4 divisors (see below), whose sum is σ = 32956926. Its totient is φ = 10985640.

The previous prime is 21971269. The next prime is 21971291. The reversal of 21971282 is 28217912.

It is a happy number.

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

It can be written as a sum of positive squares in only one way, i.e., 20802721 + 1168561 = 4561^2 + 1081^2 .

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 as a sum of consecutive naturals, namely, 5492819 + ... + 5492822.

Almost surely, 2^21971282 is an apocalyptic number.

21971282 is a deficient number, since it is larger than the sum of its proper divisors (10985644).

21971282 is a wasteful number, since it uses less digits than its factorization.

21971282 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10985643.

The product of its digits is 4032, while the sum is 32.

The square root of 21971282 is about 4687.3534110412. The cubic root of 21971282 is about 280.0819573009.

The spelling of 21971282 in words is "twenty-one million, nine hundred seventy-one thousand, two hundred eighty-two".