21173716 has 24 divisors (see below), whose sum is σ = 38142720. Its totient is φ = 10278912.

The previous prime is 21173701. The next prime is 21173717. The reversal of 21173716 is 61737112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21173717) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 43965 + ... + 44443.

It is an arithmetic number, because the mean of its divisors is an integer number (1589280).

Almost surely, 2^21173716 is an apocalyptic number.

It is an amenable number.

21173716 is a deficient number, since it is larger than the sum of its proper divisors (16969004).

21173716 is a wasteful number, since it uses less digits than its factorization.

21173716 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 783 (or 781 counting only the distinct ones).

The product of its digits is 1764, while the sum is 28.

The square root of 21173716 is about 4601.4906280465. The cubic root of 21173716 is about 276.6510744265.

It can be divided in two parts, 2 and 1173716, that multiplied together give a palindrome (2347432).

The spelling of 21173716 in words is "twenty-one million, one hundred seventy-three thousand, seven hundred sixteen".