21171430 has 24 divisors (see below), whose sum is σ = 44331408. Its totient is φ = 7258608.

The previous prime is 21171407. The next prime is 21171461. The reversal of 21171430 is 3417112.

It is a junction number, because it is equal to n+sod(n) for n = 21171398 and 21171407.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 21114 + ... + 22093.

It is an arithmetic number, because the mean of its divisors is an integer number (1847142).

Almost surely, 2^21171430 is an apocalyptic number.

21171430 is an abundant number, since it is smaller than the sum of its proper divisors (23159978).

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

21171430 is a wasteful number, since it uses less digits than its factorization.

21171430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43228 (or 43221 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 19.

The square root of 21171430 is about 4601.2422235740. The cubic root of 21171430 is about 276.6411179453.

Adding to 21171430 its reverse (3417112), we get a palindrome (24588542).

The spelling of 21171430 in words is "twenty-one million, one hundred seventy-one thousand, four hundred thirty".