21143706 has 16 divisors (see below), whose sum is σ = 42400800. Its totient is φ = 7029008.

The previous prime is 21143671. The next prime is 21143719. The reversal of 21143706 is 60734112.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2196 + ... + 6863.

It is an arithmetic number, because the mean of its divisors is an integer number (2650050).

Almost surely, 2^21143706 is an apocalyptic number.

21143706 is an abundant number, since it is smaller than the sum of its proper divisors (21257094).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21143706 is a wasteful number, since it uses less digits than its factorization.

21143706 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9453.

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

The square root of 21143706 is about 4598.2285719612. The cubic root of 21143706 is about 276.5203112958.

Adding to 21143706 its reverse (60734112), we get a palindrome (81877818).

The spelling of 21143706 in words is "twenty-one million, one hundred forty-three thousand, seven hundred six".