21021430 has 8 divisors (see below), whose sum is σ = 37838592. Its totient is φ = 8408568.

The previous prime is 21021419. The next prime is 21021431. The reversal of 21021430 is 3412012.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21021430.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021431) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 1051062 + ... + 1051081.

It is an arithmetic number, because the mean of its divisors is an integer number (4729824).

Almost surely, 2^21021430 is an apocalyptic number.

21021430 is a deficient number, since it is larger than the sum of its proper divisors (16817162).

21021430 is a wasteful number, since it uses less digits than its factorization.

21021430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2102150.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 21021430 is about 4584.9133034333. The cubic root of 21021430 is about 275.9862329477.

Adding to 21021430 its reverse (3412012), we get a palindrome (24433442).

The spelling of 21021430 in words is "twenty-one million, twenty-one thousand, four hundred thirty".