21050016 has 96 divisors (see below), whose sum is σ = 60455808. Its totient is φ = 6374400.

The previous prime is 21050011. The next prime is 21050017. The reversal of 21050016 is 61005012.

It is a tau number, because it is divible by the number of its divisors (96).

It is a junction number, because it is equal to n+sod(n) for n = 21049977 and 21050004.

It is not an unprimeable number, because it can be changed into a prime (21050011) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 125965 + ... + 126131.

It is an arithmetic number, because the mean of its divisors is an integer number (629748).

Almost surely, 2^21050016 is an apocalyptic number.

21050016 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21050016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30227904).

21050016 is an abundant number, since it is smaller than the sum of its proper divisors (39405792).

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

21050016 is a wasteful number, since it uses less digits than its factorization.

21050016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 294 (or 286 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 21050016 is about 4588.0296424500. The cubic root of 21050016 is about 276.1112762812. Note that the first 3 decimals are identical.

Adding to 21050016 its reverse (61005012), we get a palindrome (82055028).

The spelling of 21050016 in words is "twenty-one million, fifty thousand, sixteen".