21613013 has 4 divisors (see below), whose sum is σ = 22750560. Its totient is φ = 20475468.

The previous prime is 21613003. The next prime is 21613019. The reversal of 21613013 is 31031612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21613013 - 2⁶ = 21612949 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21612982 and 21613000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21613019) 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 3 ways as a sum of consecutive naturals, for example, 568745 + ... + 568782.

It is an arithmetic number, because the mean of its divisors is an integer number (5687640).

Almost surely, 2^21613013 is an apocalyptic number.

It is an amenable number.

21613013 is a deficient number, since it is larger than the sum of its proper divisors (1137547).

21613013 is a wasteful number, since it uses less digits than its factorization.

21613013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1137546.

The product of its (nonzero) digits is 108, while the sum is 17.

The square root of 21613013 is about 4648.9797805540. The cubic root of 21613013 is about 278.5512456371.

Adding to 21613013 its reverse (31031612), we get a palindrome (52644625).

The spelling of 21613013 in words is "twenty-one million, six hundred thirteen thousand, thirteen".