21049434 has 96 divisors (see below), whose sum is σ = 57148416. Its totient is φ = 5460480.

The previous prime is 21049387. The next prime is 21049493. The reversal of 21049434 is 43494012.

It is a junction number, because it is equal to n+sod(n) for n = 21049398 and 21049407.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 66244 + ... + 66560.

It is an arithmetic number, because the mean of its divisors is an integer number (595296).

Almost surely, 2^21049434 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21049434, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28574208).

21049434 is an abundant number, since it is smaller than the sum of its proper divisors (36098982).

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

21049434 is a wasteful number, since it uses less digits than its factorization.

21049434 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 380 (or 377 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 21049434 is about 4587.9662160918. The cubic root of 21049434 is about 276.1087315762.

The spelling of 21049434 in words is "twenty-one million, forty-nine thousand, four hundred thirty-four".