21016950 has 48 divisors (see below), whose sum is σ = 52496640. Its totient is φ = 5564320.

The previous prime is 21016949. The next prime is 21016979. The reversal of 21016950 is 5961012.

It is a self number, because there is not a number n which added to its sum of digits gives 21016950.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 24631 + ... + 25469.

It is an arithmetic number, because the mean of its divisors is an integer number (1093680).

Almost surely, 2^21016950 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21016950, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26248320).

21016950 is an abundant number, since it is smaller than the sum of its proper divisors (31479690).

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

21016950 is a wasteful number, since it uses less digits than its factorization.

21016950 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1021 (or 1016 counting only the distinct ones).

The product of its (nonzero) digits is 540, while the sum is 24.

The square root of 21016950 is about 4584.4247185443. The cubic root of 21016950 is about 275.9666258742.

Adding to 21016950 its reverse (5961012), we get a palindrome (26977962).

The spelling of 21016950 in words is "twenty-one million, sixteen thousand, nine hundred fifty".