21345513 has 8 divisors (see below), whose sum is σ = 32526528. Its totient is φ = 12197424.

The previous prime is 21345509. The next prime is 21345517. The reversal of 21345513 is 31554312.

It is an interprime number because it is at equal distance from previous prime (21345509) and next prime (21345517).

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

It is not a de Polignac number, because 21345513 - 2² = 21345509 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21345517) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 508206 + ... + 508247.

It is an arithmetic number, because the mean of its divisors is an integer number (4065816).

Almost surely, 2^21345513 is an apocalyptic number.

It is an amenable number.

21345513 is a deficient number, since it is larger than the sum of its proper divisors (11181015).

21345513 is a wasteful number, since it uses less digits than its factorization.

21345513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1016463.

The product of its digits is 1800, while the sum is 24.

The square root of 21345513 is about 4620.1204529752. The cubic root of 21345513 is about 277.3972803814.

Adding to 21345513 its reverse (31554312), we get a palindrome (52899825).

The spelling of 21345513 in words is "twenty-one million, three hundred forty-five thousand, five hundred thirteen".