21713830 has 8 divisors (see below), whose sum is σ = 39084912. Its totient is φ = 8685528.

The previous prime is 21713819. The next prime is 21713833. The reversal of 21713830 is 3831712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21713795 and 21713804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21713833) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 1085682 + ... + 1085701.

It is an arithmetic number, because the mean of its divisors is an integer number (4885614).

Almost surely, 2^21713830 is an apocalyptic number.

21713830 is a deficient number, since it is larger than the sum of its proper divisors (17371082).

21713830 is a wasteful number, since it uses less digits than its factorization.

21713830 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2171390.

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 21713830 is about 4659.8100819669. The cubic root of 21713830 is about 278.9836880191.

The spelling of 21713830 in words is "twenty-one million, seven hundred thirteen thousand, eight hundred thirty".