21106743 has 16 divisors (see below), whose sum is σ = 32229120. Its totient is φ = 12036096.

The previous prime is 21106721. The next prime is 21106763. The reversal of 21106743 is 34760112.

It is not a de Polignac number, because 21106743 - 2¹⁸ = 20844599 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21106763) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15496 + ... + 16802.

It is an arithmetic number, because the mean of its divisors is an integer number (2014320).

Almost surely, 2^21106743 is an apocalyptic number.

21106743 is a deficient number, since it is larger than the sum of its proper divisors (11122377).

21106743 is a wasteful number, since it uses less digits than its factorization.

21106743 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2086.

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 21106743 is about 4594.2075486421. The cubic root of 21106743 is about 276.3590815643.

Adding to 21106743 its reverse (34760112), we get a palindrome (55866855).

The spelling of 21106743 in words is "twenty-one million, one hundred six thousand, seven hundred forty-three".