21002641 has 8 divisors (see below), whose sum is σ = 23702400. Its totient is φ = 18434640.

The previous prime is 21002629. The next prime is 21002651. The reversal of 21002641 is 14620012.

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

It is a cyclic number.

It is not a de Polignac number, because 21002641 - 2⁹ = 21002129 is a prime.

It is a super-2 number, since 2×21002641² = 882221857949762, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21002621) 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, 32601 + ... + 33238.

It is an arithmetic number, because the mean of its divisors is an integer number (2962800).

Almost surely, 2^21002641 is an apocalyptic number.

It is an amenable number.

21002641 is a deficient number, since it is larger than the sum of its proper divisors (2699759).

21002641 is a wasteful number, since it uses less digits than its factorization.

21002641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65879.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 21002641 is about 4582.8638426207. The cubic root of 21002641 is about 275.9039827386.

Adding to 21002641 its reverse (14620012), we get a palindrome (35622653).

The spelling of 21002641 in words is "twenty-one million, two thousand, six hundred forty-one".