21943982 has 4 divisors (see below), whose sum is σ = 32915976. Its totient is φ = 10971990.

The previous prime is 21943973. The next prime is 21944009. The reversal of 21943982 is 28934912.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5485994 + ... + 5485997.

It is an arithmetic number, because the mean of its divisors is an integer number (8228994).

Almost surely, 2^21943982 is an apocalyptic number.

21943982 is a deficient number, since it is larger than the sum of its proper divisors (10971994).

21943982 is a wasteful number, since it uses less digits than its factorization.

21943982 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10971993.

The product of its digits is 31104, while the sum is 38.

The square root of 21943982 is about 4684.4404148201. The cubic root of 21943982 is about 279.9659057126.

The spelling of 21943982 in words is "twenty-one million, nine hundred forty-three thousand, nine hundred eighty-two".