21404470 has 8 divisors (see below), whose sum is σ = 38528064. Its totient is φ = 8561784.

The previous prime is 21404459. The next prime is 21404491. The reversal of 21404470 is 7440412.

21404470 = 1025² + 1026² + ... + 1044².

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

It is a congruent number.

It is an unprimeable number.

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, 1070214 + ... + 1070233.

It is an arithmetic number, because the mean of its divisors is an integer number (4816008).

Almost surely, 2^21404470 is an apocalyptic number.

21404470 is a deficient number, since it is larger than the sum of its proper divisors (17123594).

21404470 is a wasteful number, since it uses less digits than its factorization.

21404470 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2140454.

The product of its (nonzero) digits is 896, while the sum is 22.

The square root of 21404470 is about 4626.4965146426. The cubic root of 21404470 is about 277.6524390384.

Adding to 21404470 its reverse (7440412), we get a palindrome (28844882).

The spelling of 21404470 in words is "twenty-one million, four hundred four thousand, four hundred seventy".