21641016 has 16 divisors (see below), whose sum is σ = 54102600. Its totient is φ = 7213664.

The previous prime is 21641003. The next prime is 21641027. The reversal of 21641016 is 61014612.

It is a junction number, because it is equal to n+sod(n) for n = 21640983 and 21641001.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 450831 + ... + 450878.

Almost surely, 2^21641016 is an apocalyptic number.

It is an amenable number.

21641016 is an abundant number, since it is smaller than the sum of its proper divisors (32461584).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21641016 is a wasteful number, since it uses less digits than its factorization.

21641016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 901718 (or 901714 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 21641016 is about 4651.9905416929. The cubic root of 21641016 is about 278.6714957866.

Adding to 21641016 its reverse (61014612), we get a palindrome (82655628).

The spelling of 21641016 in words is "twenty-one million, six hundred forty-one thousand, sixteen".