21997282 has 8 divisors (see below), whose sum is σ = 33140700. Its totient is φ = 10950384.

The previous prime is 21997253. The next prime is 21997301. The reversal of 21997282 is 28279912.

It can be written as a sum of positive squares in 2 ways, for example, as 20602521 + 1394761 = 4539^2 + 1181^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23557 + ... + 24472.

Almost surely, 2^21997282 is an apocalyptic number.

21997282 is a deficient number, since it is larger than the sum of its proper divisors (11143418).

21997282 is a wasteful number, since it uses less digits than its factorization.

21997282 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48260.

The product of its digits is 36288, while the sum is 40.

The square root of 21997282 is about 4690.1260111003. The cubic root of 21997282 is about 280.1923932829.

The spelling of 21997282 in words is "twenty-one million, nine hundred ninety-seven thousand, two hundred eighty-two".