21819126 has 32 divisors (see below), whose sum is σ = 52807680. Its totient is φ = 5867136.

The previous prime is 21819121. The next prime is 21819137. The reversal of 21819126 is 62191812.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21819093 and 21819102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21819121) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14566 + ... + 15993.

It is an arithmetic number, because the mean of its divisors is an integer number (1650240).

Almost surely, 2^21819126 is an apocalyptic number.

21819126 is an abundant number, since it is smaller than the sum of its proper divisors (30988554).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21819126 is a wasteful number, since it uses less digits than its factorization.

21819126 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30588.

The product of its digits is 1728, while the sum is 30.

The square root of 21819126 is about 4671.0947325012. The cubic root of 21819126 is about 279.4339158262.

It can be divided in two parts, 21819 and 126, that added together give a triangular number (21945 = T₂₀₉).

The spelling of 21819126 in words is "twenty-one million, eight hundred nineteen thousand, one hundred twenty-six".