21002613 has 8 divisors (see below), whose sum is σ = 28094208. Its totient is φ = 13956384.

The previous prime is 21002591. The next prime is 21002621. The reversal of 21002613 is 31620012.

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

It is not a de Polignac number, because 21002613 - 2⁶ = 21002549 is a prime.

It is a super-2 number, since 2×21002613² = 882219505655538, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21002592 and 21002601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002623) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10245 + ... + 12122.

It is an arithmetic number, because the mean of its divisors is an integer number (3511776).

Almost surely, 2^21002613 is an apocalyptic number.

It is an amenable number.

21002613 is a deficient number, since it is larger than the sum of its proper divisors (7091595).

21002613 is a wasteful number, since it uses less digits than its factorization.

21002613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22683.

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 21002613 is about 4582.8607877613. The cubic root of 21002613 is about 275.9038601300.

Adding to 21002613 its reverse (31620012), we get a palindrome (52622625).

The spelling of 21002613 in words is "twenty-one million, two thousand, six hundred thirteen".