21791230 has 16 divisors (see below), whose sum is σ = 39762864. Its totient is φ = 8596800.

The previous prime is 21791227. The next prime is 21791257. The reversal of 21791230 is 3219712.

It is a junction number, because it is equal to n+sod(n) for n = 21791195 and 21791204.

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 7 ways as a sum of consecutive naturals, for example, 14196 + ... + 15655.

It is an arithmetic number, because the mean of its divisors is an integer number (2485179).

Almost surely, 2^21791230 is an apocalyptic number.

21791230 is a deficient number, since it is larger than the sum of its proper divisors (17971634).

21791230 is a wasteful number, since it uses less digits than its factorization.

21791230 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29931.

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 21791230 is about 4668.1077536835. The cubic root of 21791230 is about 279.3147785623.

The spelling of 21791230 in words is "twenty-one million, seven hundred ninety-one thousand, two hundred thirty".