21430515 has 16 divisors (see below), whose sum is σ = 34347168. Its totient is φ = 11410176.

The previous prime is 21430481. The next prime is 21430529. The reversal of 21430515 is 51503412.

It is not a de Polignac number, because 21430515 - 2⁸ = 21430259 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21430491 and 21430500.

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 15 ways as a sum of consecutive naturals, for example, 14239 + ... + 15671.

It is an arithmetic number, because the mean of its divisors is an integer number (2146698).

Almost surely, 2^21430515 is an apocalyptic number.

21430515 is a deficient number, since it is larger than the sum of its proper divisors (12916653).

21430515 is a wasteful number, since it uses less digits than its factorization.

21430515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2438.

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 21430515 is about 4629.3104238104. The cubic root of 21430515 is about 277.7650093983.

Adding to 21430515 its reverse (51503412), we get a palindrome (72933927).

It can be divided in two parts, 21430 and 515, that added together give a triangular number (21945 = T₂₀₉).

The spelling of 21430515 in words is "twenty-one million, four hundred thirty thousand, five hundred fifteen".