21179830 has 32 divisors (see below), whose sum is σ = 43732224. Its totient is φ = 7234656.

The previous prime is 21179827. The next prime is 21179843. The reversal of 21179830 is 3897112.

It is a junction number, because it is equal to n+sod(n) for n = 21179792 and 21179801.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30669 + ... + 31351.

It is an arithmetic number, because the mean of its divisors is an integer number (1366632).

Almost surely, 2^21179830 is an apocalyptic number.

21179830 is an abundant number, since it is smaller than the sum of its proper divisors (22552394).

21179830 is a wasteful number, since it uses less digits than its factorization.

21179830 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1140.

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 21179830 is about 4602.1549300301. The cubic root of 21179830 is about 276.6776999197.

The spelling of 21179830 in words is "twenty-one million, one hundred seventy-nine thousand, eight hundred thirty".