21982743 has 6 divisors (see below), whose sum is σ = 31752864. Its totient is φ = 14655156.

The previous prime is 21982739. The next prime is 21982769. The reversal of 21982743 is 34728912.

It is not a de Polignac number, because 21982743 - 2² = 21982739 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21982698 and 21982707.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21982243) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1221255 + ... + 1221272.

It is an arithmetic number, because the mean of its divisors is an integer number (5292144).

Almost surely, 2^21982743 is an apocalyptic number.

21982743 is a deficient number, since it is larger than the sum of its proper divisors (9770121).

21982743 is a wasteful number, since it uses less digits than its factorization.

21982743 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2442533 (or 2442530 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 21982743 is about 4688.5757965506. The cubic root of 21982743 is about 280.1306490632.

The spelling of 21982743 in words is "twenty-one million, nine hundred eighty-two thousand, seven hundred forty-three".