21820126 has 8 divisors (see below), whose sum is σ = 33426720. Its totient is φ = 10677888.

The previous prime is 21820111. The next prime is 21820133. The reversal of 21820126 is 62102812.

21820126 = T₉₄₀ + T₉₄₁ + ... + T₉₈₆.

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

It is a super-2 number, since 2×21820126² = 952235797311752, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21820097 and 21820106.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 115971 + ... + 116158.

It is an arithmetic number, because the mean of its divisors is an integer number (4178340).

Almost surely, 2^21820126 is an apocalyptic number.

21820126 is a deficient number, since it is larger than the sum of its proper divisors (11606594).

21820126 is a wasteful number, since it uses less digits than its factorization.

21820126 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 232178.

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 21820126 is about 4671.2017725635. The cubic root of 21820126 is about 279.4381847055.

Adding to 21820126 its reverse (62102812), we get a palindrome (83922938).

The spelling of 21820126 in words is "twenty-one million, eight hundred twenty thousand, one hundred twenty-six".