21173704 has 16 divisors (see below), whose sum is σ = 42036300. Its totient is φ = 9964032.

The previous prime is 21173701. The next prime is 21173717. The reversal of 21173704 is 40737112.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 17556100 + 3617604 = 4190^2 + 1902^2 .

It is not an unprimeable number, because it can be changed into a prime (21173701) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 77709 + ... + 77980.

Almost surely, 2^21173704 is an apocalyptic number.

It is an amenable number.

21173704 is a deficient number, since it is larger than the sum of its proper divisors (20862596).

21173704 is a wasteful number, since it uses less digits than its factorization.

21173704 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155712 (or 155708 counting only the distinct ones).

The product of its (nonzero) digits is 1176, while the sum is 25.

The square root of 21173704 is about 4601.4893241211. The cubic root of 21173704 is about 276.6510221634.

The spelling of 21173704 in words is "twenty-one million, one hundred seventy-three thousand, seven hundred four".