21011716 has 12 divisors (see below), whose sum is σ = 40113360. Its totient is φ = 9550760.

The previous prime is 21011713. The next prime is 21011741. The reversal of 21011716 is 61711012.

It is a junction number, because it is equal to n+sod(n) for n = 21011693 and 21011702.

It is not an unprimeable number, because it can be changed into a prime (21011713) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 238726 + ... + 238813.

It is an arithmetic number, because the mean of its divisors is an integer number (3342780).

Almost surely, 2^21011716 is an apocalyptic number.

It is an amenable number.

21011716 is a deficient number, since it is larger than the sum of its proper divisors (19101644).

21011716 is a wasteful number, since it uses less digits than its factorization.

21011716 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 477554 (or 477552 counting only the distinct ones).

The product of its (nonzero) digits is 84, while the sum is 19.

The square root of 21011716 is about 4583.8538371113. The cubic root of 21011716 is about 275.9437153307.

Adding to 21011716 its reverse (61711012), we get a palindrome (82722728).

The spelling of 21011716 in words is "twenty-one million, eleven thousand, seven hundred sixteen".