21170613 has 16 divisors (see below), whose sum is σ = 29293056. Its totient is φ = 13585920.

The previous prime is 21170587. The next prime is 21170629. The reversal of 21170613 is 31607112.

It is not a de Polignac number, because 21170613 - 2⁵ = 21170581 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21170613.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21170113) 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 15 ways as a sum of consecutive naturals, for example, 21181 + ... + 22157.

It is an arithmetic number, because the mean of its divisors is an integer number (1830816).

Almost surely, 2^21170613 is an apocalyptic number.

It is an amenable number.

21170613 is a deficient number, since it is larger than the sum of its proper divisors (8122443).

21170613 is a wasteful number, since it uses less digits than its factorization.

21170613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1244.

The product of its (nonzero) digits is 252, while the sum is 21.

The square root of 21170613 is about 4601.1534423446. The cubic root of 21170613 is about 276.6375593965.

Adding to 21170613 its reverse (31607112), we get a palindrome (52777725).

The spelling of 21170613 in words is "twenty-one million, one hundred seventy thousand, six hundred thirteen".