21168746 has 4 divisors (see below), whose sum is σ = 31753122. Its totient is φ = 10584372.

The previous prime is 21168713. The next prime is 21168767. The reversal of 21168746 is 64786112.

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

It can be written as a sum of positive squares in only one way, i.e., 20802721 + 366025 = 4561^2 + 605^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5292185 + ... + 5292188.

Almost surely, 2^21168746 is an apocalyptic number.

21168746 is a deficient number, since it is larger than the sum of its proper divisors (10584376).

21168746 is a wasteful number, since it uses less digits than its factorization.

21168746 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10584375.

The product of its digits is 16128, while the sum is 35.

The square root of 21168746 is about 4600.9505539616. The cubic root of 21168746 is about 276.6294270937.

The spelling of 21168746 in words is "twenty-one million, one hundred sixty-eight thousand, seven hundred forty-six".