21007016 has 16 divisors (see below), whose sum is σ = 39436800. Its totient is φ = 10490544.

The previous prime is 21007013. The next prime is 21007067. The reversal of 21007016 is 61070012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21006985 and 21007003.

It is not an unprimeable number, because it can be changed into a prime (21007013) 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, 11801 + ... + 13463.

It is an arithmetic number, because the mean of its divisors is an integer number (2464800).

Almost surely, 2^21007016 is an apocalyptic number.

It is an amenable number.

21007016 is a deficient number, since it is larger than the sum of its proper divisors (18429784).

21007016 is a wasteful number, since it uses less digits than its factorization.

21007016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3248 (or 3244 counting only the distinct ones).

The product of its (nonzero) digits is 84, while the sum is 17.

The square root of 21007016 is about 4583.3411393873. The cubic root of 21007016 is about 275.9231389981.

Adding to 21007016 its reverse (61070012), we get a palindrome (82077028).

The spelling of 21007016 in words is "twenty-one million, seven thousand, sixteen".