21470513 has 16 divisors (see below), whose sum is σ = 23328000. Its totient is φ = 19698192.

The previous prime is 21470509. The next prime is 21470521. The reversal of 21470513 is 31507412.

It is a cyclic number.

It is not a de Polignac number, because 21470513 - 2² = 21470509 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21470543) 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 15 ways as a sum of consecutive naturals, for example, 119858 + ... + 120036.

It is an arithmetic number, because the mean of its divisors is an integer number (1458000).

Almost surely, 2^21470513 is an apocalyptic number.

It is an amenable number.

21470513 is a deficient number, since it is larger than the sum of its proper divisors (1857487).

21470513 is a wasteful number, since it uses less digits than its factorization.

21470513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 364.

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 21470513 is about 4633.6284917978. The cubic root of 21470513 is about 277.9377092464.

Adding to 21470513 its reverse (31507412), we get a palindrome (52977925).

The spelling of 21470513 in words is "twenty-one million, four hundred seventy thousand, five hundred thirteen".