21051430 has 32 divisors (see below), whose sum is σ = 40318560. Its totient is φ = 7891200.

The previous prime is 21051427. The next prime is 21051431. The reversal of 21051430 is 3415012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21051431) 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, 18642 + ... + 19738.

It is an arithmetic number, because the mean of its divisors is an integer number (1259955).

Almost surely, 2^21051430 is an apocalyptic number.

21051430 is a deficient number, since it is larger than the sum of its proper divisors (19267130).

21051430 is a wasteful number, since it uses less digits than its factorization.

21051430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1224.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 21051430 is about 4588.1837365127. The cubic root of 21051430 is about 276.1174585822.

Adding to 21051430 its reverse (3415012), we get a palindrome (24466442).

The spelling of 21051430 in words is "twenty-one million, fifty-one thousand, four hundred thirty".