21174730 has 32 divisors (see below), whose sum is σ = 39507840. Its totient is φ = 8164800.

The previous prime is 21174691. The next prime is 21174733. The reversal of 21174730 is 3747112.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21174695 and 21174704.

It is not an unprimeable number, because it can be changed into a prime (21174733) 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 15 ways as a sum of consecutive naturals, for example, 55681 + ... + 56059.

It is an arithmetic number, because the mean of its divisors is an integer number (1234620).

Almost surely, 2^21174730 is an apocalyptic number.

21174730 is a deficient number, since it is larger than the sum of its proper divisors (18333110).

21174730 is a wasteful number, since it uses less digits than its factorization.

21174730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 574.

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

The square root of 21174730 is about 4601.6008084144. The cubic root of 21174730 is about 276.6554905890.

It can be divided in two parts, 21174 and 730, that added together give a square (21904 = 148²).

The spelling of 21174730 in words is "twenty-one million, one hundred seventy-four thousand, seven hundred thirty".